GE has said that it will invest $1.4 billion in clean technology research and development in 2008 as part of its Ecomagination initiative. As of October 2008, the scheme had resulted in 70 green products being brought to market, ranging from halogen lamps to biogas engines. In 2007, GE raised the annual revenue target for its Ecomagination initiative from $20 billion in 2010 to $25 billion following positive market response to its new product lines. In 2010, GE continued to raise its investment by adding $10 billion into Ecomagination over the next five years.


Short Films, Big Ideas was launched at the 2011 Toronto International Film Festival in partnership with cinelan. Stories included breakthroughs in Slingshot (water vapor distillation system), cancer research, energy production, pain management and food access. Each of the 30 films received world premiere screenings at a major international film festival, including the Sundance Film Festival and the Tribeca Film Festival. The winning amateur director film, The Cyborg Foundation, was awarded a US$100,000 prize at the 2013 at Sundance Film Festival.[citation needed] According to GE, the campaign garnered more than 1.5 billion total media impressions, 14 million online views, and was seen in 156 countries.[citation needed]


In April 2014, it was announced that GE was in talks to acquire the global power division of French engineering group Alstom for a figure of around $13 billion. A rival joint bid was submitted in June 2014 by Siemens and Mitsubishi Heavy Industries (MHI) with Siemens seeking to acquire Alstom's gas turbine business for €3.9 billion, and MHI proposing a joint venture in steam turbines, plus a €3.1 billion cash investment. In June 2014 a formal offer From GE worth $17 billion was agreed by the Alstom board. Part of the transaction involved the French government taking a 20% stake in Alstom to help secure France's energy and transport interests, and French jobs. A rival offer from Siemens-Mitsubishi Heavy Industries was rejected. The acquisition was expected to be completed in 2015.


GE is a multinational conglomerate headquartered in Fairfield, Connecticut. Its main offices are located at 30 Rockefeller Plaza at Rockefeller Center in New York City, known now as the Comcast Building. It was formerly known as the GE Building for the prominent GE logo on the roof; NBC's headquarters and main studios are also located in the building. Through its RCA subsidiary, it has been associated with the center since its construction in the 1930s. GE moved its corporate headquarters from the GE Building on Lexington Avenue to Fairfield in 1974.


In 1983, New York State Attorney General Robert Abrams filed suit in the United States District Court for the Northern District of New York to compel GE to pay for the cleanup of what was claimed to be more than 100,000 tons of chemicals dumped from their plant in Waterford, New York. In 1999, the company agreed to pay a $250 million settlement in connection with claims it polluted the Housatonic River (Pittsfield, Massachusetts) and other sites with polychlorinated biphenyls (PCBs) and other hazardous substances.


The Continental Army was created on 14 June 1775 by the Continental Congress as a unified army for the colonies to fight Great Britain, with George Washington appointed as its commander. The army was initially led by men who had served in the British Army or colonial militias and who brought much of British military heritage with them. As the Revolutionary War progressed, French aid, resources, and military thinking influenced the new army. A number of European soldiers came on their own to help, such as Friedrich Wilhelm von Steuben, who taught the army Prussian tactics and organizational skills.


The Vietnam War is often regarded as a low point for the U.S. Army due to the use of drafted personnel, the unpopularity of the war with the American public, and frustrating restrictions placed on the military by American political leaders. While American forces had been stationed in the Republic of Vietnam since 1959, in intelligence & advising/training roles, they did not deploy in large numbers until 1965, after the Gulf of Tonkin Incident. American forces effectively established and maintained control of the "traditional" battlefield, however they struggled to counter the guerrilla hit and run tactics of the communist Viet Cong and the North Vietnamese Army. On a tactical level, American soldiers (and the U.S. military as a whole) did not lose a sizable battle.


By the twentieth century, the U.S. Army had mobilized the U.S. Volunteers on four separate occasions during each of the major wars of the nineteenth century. During World War I, the "National Army" was organized to fight the conflict, replacing the concept of U.S. Volunteers. It was demobilized at the end of World War I, and was replaced by the Regular Army, the Organized Reserve Corps, and the State Militias. In the 1920s and 1930s, the "career" soldiers were known as the "Regular Army" with the "Enlisted Reserve Corps" and "Officer Reserve Corps" augmented to fill vacancies when needed.


The army is led by a civilian Secretary of the Army, who has the statutory authority to conduct all the affairs of the army under the authority, direction and control of the Secretary of Defense. The Chief of Staff of the Army, who is the highest-ranked military officer in the army, serves as the principal military adviser and executive agent for the Secretary of the Army, i.e., its service chief; and as a member of the Joint Chiefs of Staff, a body composed of the service chiefs from each of the four military services belonging to the Department of Defense who advise the President of the United States, the Secretary of Defense, and the National Security Council on operational military matters, under the guidance of the Chairman and Vice Chairman of the Joint Chiefs of Staff. In 1986, the Goldwater–Nichols Act mandated that operational control of the services follows a chain of command from the President to the Secretary of Defense directly to the unified combatant commanders, who have control of all armed forces units in their geographic or function area of responsibility. Thus, the secretaries of the military departments (and their respective service chiefs underneath them) only have the responsibility to organize, train and equip their service components. The army provides trained forces to the combatant commanders for use as directed by the Secretary of Defense.


The United States Army (USA) is the largest branch of the United States Armed Forces and performs land-based military operations. It is one of the seven uniformed services of the United States and is designated as the Army of the United States in the United States Constitution, Article 2, Section 2, Clause 1 and United States Code, Title 10, Subtitle B, Chapter 301, Section 3001. As the largest and senior branch of the U.S. military, the modern U.S. Army has its roots in the Continental Army, which was formed (14 June 1775) to fight the American Revolutionary War (1775–83)—before the U.S. was established as a country. After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784, to replace the disbanded Continental Army. The United States Army considers itself descended from the Continental Army, and dates its institutional inception from the origin of that armed force in 1775.


The War of 1812, the second and last American war against the United Kingdom, was less successful for the U.S. than the Revolution and Northwest Indian War against natives had been, though it ended on a high note for Americans as well. After the taking control of Lake Erie in 1813, the Americans were able to seize parts of western Upper Canada, burn York and defeat Tecumseh, which caused his Indian Confederacy to collapse. Following ending victories in the province of Upper Canada, which dubbed the U.S. Army "Regulars, by God!", British troops were able to capture and burn Washington. The regular army, however, proved they were professional and capable of defeating the British army during the invasions of Plattsburgh and Baltimore, prompting British agreement on the previously rejected terms of a status quo ante bellum. Two weeks after a treaty was signed (but not ratified), Andrew Jackson defeated the British in the Battle of New Orleans and became a national hero. Per the treaty both sides returned to the status quo with no victor.


After the war, though, the Continental Army was quickly given land certificates and disbanded in a reflection of the republican distrust of standing armies. State militias became the new nation's sole ground army, with the exception of a regiment to guard the Western Frontier and one battery of artillery guarding West Point's arsenal. However, because of continuing conflict with Native Americans, it was soon realized that it was necessary to field a trained standing army. The Regular Army was at first very small, and after General St. Clair's defeat at the Battle of the Wabash, the Regular Army was reorganized as the Legion of the United States, which was established in 1791 and renamed the "United States Army" in 1796.


Collective training at the unit level takes place at the unit's assigned station, but the most intensive training at higher echelons is conducted at the three combat training centers (CTC); the National Training Center (NTC) at Fort Irwin, California, the Joint Readiness Training Center (JRTC) at Fort Polk, Louisiana, and the Joint Multinational Training Center (JMRC) at the Hohenfels Training Area in Hohenfels, Germany. ARFORGEN is the Army Force Generation process approved in 2006 to meet the need to continuously replenish forces for deployment, at unit level, and for other echelons as required by the mission. Individual-level replenishment still requires training at a unit level, which is conducted at the continental US (CONUS) replacement center at Fort Bliss, in New Mexico and Texas, before their individual deployment.


For the first two years Confederate forces did well in set battles but lost control of the border states. The Confederates had the advantage of defending a very large country in an area where disease caused twice as many deaths as combat. The Union pursued a strategy of seizing the coastline, blockading the ports, and taking control of the river systems. By 1863 the Confederacy was being strangled. Its eastern armies fought well, but the western armies were defeated one after another until the Union forces captured New Orleans in 1862 along with the Tennessee River. In the famous Vicksburg Campaign of 1862–63, Ulysses Grant seized the Mississippi River and cut off the Southwest. Grant took command of Union forces in 1864 and after a series of battles with very heavy casualties, he had Lee under siege in Richmond as William T. Sherman captured Atlanta and marched through Georgia and the Carolinas. The Confederate capital was abandoned in April 1865 and Lee subsequently surrendered his army at Appomattox Court House; all other Confederate armies surrendered within a few months.


The end of World War II set the stage for the East–West confrontation known as the Cold War. With the outbreak of the Korean War, concerns over the defense of Western Europe rose. Two corps, V and VII, were reactivated under Seventh United States Army in 1950 and American strength in Europe rose from one division to four. Hundreds of thousands of U.S. troops remained stationed in West Germany, with others in Belgium, the Netherlands and the United Kingdom, until the 1990s in anticipation of a possible Soviet attack.


The United States joined World War II in December 1941 after the Japanese attack on Pearl Harbor. On the European front, U.S. Army troops formed a significant portion of the forces that captured North Africa and Sicily, and later fought in Italy. On D-Day, June 6, 1944, and in the subsequent liberation of Europe and defeat of Nazi Germany, millions of U.S. Army troops played a central role. In the Pacific War, U.S. Army soldiers participated alongside the United States Marine Corps in capturing the Pacific Islands from Japanese control. Following the Axis surrenders in May (Germany) and August (Japan) of 1945, army troops were deployed to Japan and Germany to occupy the two defeated nations. Two years after World War II, the Army Air Forces separated from the army to become the United States Air Force in September 1947 after decades of attempting to separate. Also, in 1948, the army was desegregated by order of President Harry S. Truman.


The Total Force Policy was adopted by Chief of Staff of the Army General Creighton Abrams in the aftermath of the Vietnam War and involves treating the three components of the army – the Regular Army, the Army National Guard and the Army Reserve as a single force. Believing that no U.S. president should be able to take the United States (and more specifically the U.S. Army) to war without the support of the American people, General Abrams intertwined the structure of the three components of the army in such a way as to make extended operations impossible, without the involvement of both the Army National Guard and the Army Reserve.


In response to the September 11 attacks, and as part of the Global War on Terror, U.S. and NATO forces invaded Afghanistan in October 2001, displacing the Taliban government. The U.S. Army also led the combined U.S. and allied invasion of Iraq in 2003. It served as the primary source for ground forces with its ability to sustain short and long-term deployment operations. In the following years the mission changed from conflict between regular militaries to counterinsurgency, resulting in the deaths of more than 4,000 U.S service members (as of March 2008) and injuries to thousands more. 23,813 insurgents were killed in Iraq between 2003–2011.


Currently, the army is divided into the Regular Army, the Army Reserve, and the Army National Guard. The army is also divided into major branches such as Air Defense Artillery, Infantry, Aviation, Signal Corps, Corps of Engineers, and Armor. Before 1903 members of the National Guard were considered state soldiers unless federalized (i.e., activated) by the President. Since the Militia Act of 1903 all National Guard soldiers have held dual status: as National Guardsmen under the authority of the governor of their state or territory and, when activated, as a reserve of the U.S. Army under the authority of the President.


The U.S. Army currently consists of 10 active divisions as well as several independent units. The force is in the process of contracting after several years of growth. In June 2013, the Army announced plans to downsize to 32 active combat brigade teams by 2015 to match a reduction in active duty strength to 490,000 soldiers. Army Chief of Staff Raymond Odierno has projected that by 2018 the Army will eventually shrink to "450,000 in the active component, 335,000 in the National Guard and 195,000 in U.S. Army Reserve."


Training in the U.S. Army is generally divided into two categories – individual and collective. Basic training consists of 10 weeks for most recruits followed by Advanced Individualized Training (AIT) where they receive training for their military occupational specialties (MOS). Some individuals MOSs range anywhere from 14–20 weeks of One Station Unit Training (OSUT), which combines Basic Training and AIT. The length of AIT school varies by the MOS The length of time spent in AIT depends on the MOS of the soldier, and some highly technical MOS training may require many months (e.g., foreign language translators). Depending on the needs of the army, Basic Combat Training for combat arms soldiers is conducted at a number of locations, but two of the longest-running are the Armor School and the Infantry School, both at Fort Benning, Georgia.


Many units are supplemented with a variety of specialized weapons, including the M249 SAW (Squad Automatic Weapon), to provide suppressive fire at the fire-team level. Indirect fire is provided by the M203 grenade launcher. The M1014 Joint Service Combat Shotgun or the Mossberg 590 Shotgun are used for door breaching and close-quarters combat. The M14EBR is used by designated marksmen. Snipers use the M107 Long Range Sniper Rifle, the M2010 Enhanced Sniper Rifle, and the M110 Semi-Automatic Sniper Rifle.


The Pentagon bought 25,000 MRAP vehicles since 2007 in 25 variants through rapid acquisition with no long-term plans for the platforms. The Army plans to divest 7,456 vehicles and retain 8,585. Of the total number of vehicles the Army will keep, 5,036 will be put in storage, 1,073 will be used for training, and the remainder will be spread across the active force. The Oshkosh M-ATV will be kept the most at 5,681 vehicles, as it is smaller and lighter than other MRAPs for off-road mobility. The other most retained vehicle will be the Navistar MaxxPro Dash with 2,633 vehicles, plus 301 Maxxpro ambulances. Thousands of other MRAPs like the Cougar, BAE Caiman, and larger MaxxPros will be disposed of.


The U.S. Army black beret (having been permanently replaced with the patrol cap) is no longer worn with the new ACU for garrison duty. After years of complaints that it wasn't suited well for most work conditions, Army Chief of Staff General Martin Dempsey eliminated it for wear with the ACU in June 2011. Soldiers still wear berets who are currently in a unit in jump status, whether the wearer is parachute-qualified, or not (maroon beret), Members of the 75th Ranger Regiment and the Airborne and Ranger Training Brigade (tan beret), and Special Forces (rifle green beret) and may wear it with the Army Service Uniform for non-ceremonial functions. Unit commanders may still direct the wear of patrol caps in these units in training environments or motor pools.


As a uniformed military service, the Army is part of the Department of the Army, which is one of the three military departments of the Department of Defense. The U.S. Army is headed by a civilian senior appointed civil servant, the Secretary of the Army (SECARMY), and by a chief military officer, the Chief of Staff of the Army (CSA) who is also a member of the Joint Chiefs of Staff. In the fiscal year 2016, the projected end strength for the Regular Army (USA) was 475,000 soldiers; the Army National Guard (ARNG) had 342,000 soldiers, and the United States Army Reserve (USAR) had 198,000 soldiers; the combined-component strength of the U.S. Army was 1,015,000 soldiers. As a branch of the armed forces, the mission of the U.S. Army is "to fight and win our Nation's wars, by providing prompt, sustained, land dominance, across the full range of military operations and the spectrum of conflict, in support of combatant commanders." The service participates in conflicts worldwide and is the major ground-based offensive and defensive force.


The army's major campaign against the Indians was fought in Florida against Seminoles. It took long wars (1818–58) to finally defeat the Seminoles and move them to Oklahoma. The usual strategy in Indian wars was to seize control of the Indians winter food supply, but that was no use in Florida where there was no winter. The second strategy was to form alliances with other Indian tribes, but that too was useless because the Seminoles had destroyed all the other Indians when they entered Florida in the late eighteenth century.


During the Cold War, American troops and their allies fought Communist forces in Korea and Vietnam. The Korean War began in 1950, when the Soviets walked out of a U.N. Security meeting, removing their possible veto. Under a United Nations umbrella, hundreds of thousands of U.S. troops fought to prevent the takeover of South Korea by North Korea, and later, to invade the northern nation. After repeated advances and retreats by both sides, and the PRC People's Volunteer Army's entry into the war, the Korean Armistice Agreement returned the peninsula to the status quo in 1953.


By 1989 Germany was nearing reunification and the Cold War was coming to a close. Army leadership reacted by starting to plan for a reduction in strength. By November 1989 Pentagon briefers were laying out plans to reduce army end strength by 23%, from 750,000 to 580,000. A number of incentives such as early retirement were used. In 1990 Iraq invaded its smaller neighbor, Kuwait, and U.S. land forces, quickly deployed to assure the protection of Saudi Arabia. In January 1991 Operation Desert Storm commenced, a U.S.-led coalition which deployed over 500,000 troops, the bulk of them from U.S. Army formations, to drive out Iraqi forces. The campaign ended in total victory, as Western coalition forces routed the Iraqi Army, organized along Soviet lines, in just one hundred hours.


The task of organizing the U.S. Army commenced in 1775. In the first one hundred years of its existence, the United States Army was maintained as a small peacetime force to man permanent forts and perform other non-wartime duties such as engineering and construction works. During times of war, the U.S. Army was augmented by the much larger United States Volunteers which were raised independently by various state governments. States also maintained full-time militias which could also be called into the service of the army.


The United States Army is made up of three components: the active component, the Regular Army; and two reserve components, the Army National Guard and the Army Reserve. Both reserve components are primarily composed of part-time soldiers who train once a month, known as battle assemblies or unit training assemblies (UTAs), and conduct two to three weeks of annual training each year. Both the Regular Army and the Army Reserve are organized under Title 10 of the United States Code, while the National Guard is organized under Title 32. While the Army National Guard is organized, trained and equipped as a component of the U.S. Army, when it is not in federal service it is under the command of individual state and territorial governors; the District of Columbia National Guard, however, reports to the U.S. President, not the district's mayor, even when not federalized. Any or all of the National Guard can be federalized by presidential order and against the governor's wishes.


Following their basic and advanced training at the individual-level, soldiers may choose to continue their training and apply for an "additional skill identifier" (ASI). The ASI allows the army to take a wide ranging MOS and focus it into a more specific MOS. For example, a combat medic, whose duties are to provide pre-hospital emergency treatment, may receive ASI training to become a cardiovascular specialist, a dialysis specialist, or even a licensed practical nurse. For commissioned officers, ASI training includes pre-commissioning training either at USMA, or via ROTC, or by completing OCS. After commissioning, officers undergo branch specific training at the Basic Officer Leaders Course, (formerly called Officer Basic Course), which varies in time and location according their future assignments. Further career development is available through the Army Correspondence Course Program.


The army has relied heavily on tents to provide the various facilities needed while on deployment. The most common tent uses for the military are as temporary barracks (sleeping quarters), DFAC buildings (dining facilities), forward operating bases (FOBs), after action review (AAR), tactical operations center (TOC), morale, welfare, and recreation (MWR) facilities, and security checkpoints. Furthermore, most of these tents are set up and operated through the support of Natick Soldier Systems Center.


The American Civil War was the costliest war for the U.S. in terms of casualties. After most slave states, located in the southern U.S., formed the Confederate States, C.S. troops led by former U.S. Army officers, mobilized a very large fraction of Southern white manpower. Forces of the United States (the "Union" or "the North") formed the Union Army consisting of a small body of regular army units and a large body of volunteer units raised from every state, north and south, except South Carolina.[citation needed]


Starting in 1910, the army began acquiring fixed-wing aircraft. In 1910, Mexico was having a civil war, peasant rebels fighting government soldiers. The army was deployed to American towns near the border to ensure safety to lives and property. In 1916, Pancho Villa, a major rebel leader, attacked Columbus, New Mexico, prompting a U.S. intervention in Mexico until 7 February 1917. They fought the rebels and the Mexican federal troops until 1918. The United States joined World War I in 1917 on the side of Britain, France, Russia, Italy and other allies. U.S. troops were sent to the Western Front and were involved in the last offensives that ended the war. With the armistice in November 1918, the army once again decreased its forces.


During the 1960s the Department of Defense continued to scrutinize the reserve forces and to question the number of divisions and brigades as well as the redundancy of maintaining two reserve components, the Army National Guard and the Army Reserve. In 1967 Secretary of Defense Robert McNamara decided that 15 combat divisions in the Army National Guard were unnecessary and cut the number to 8 divisions (1 mechanized infantry, 2 armored, and 5 infantry), but increased the number of brigades from 7 to 18 (1 airborne, 1 armored, 2 mechanized infantry, and 14 infantry). The loss of the divisions did not set well with the states. Their objections included the inadequate maneuver element mix for those that remained and the end to the practice of rotating divisional commands among the states that supported them. Under the proposal, the remaining division commanders were to reside in the state of the division base. No reduction, however, in total Army National Guard strength was to take place, which convinced the governors to accept the plan. The states reorganized their forces accordingly between 1 December 1967 and 1 May 1968.


On September 11, 2001, 53 Army civilians (47 employees and six contractors) and 22 soldiers were among the 125 victims killed in the Pentagon in a terrorist attack when American Airlines Flight 77 commandeered by five Al-Qaeda hijackers slammed into the western side of the building, as part of the September 11 attacks. Lieutenant General Timothy Maude was the highest-ranking military official killed at the Pentagon, and the most senior U.S. Army officer killed by foreign action since the death of Lieutenant General Simon B. Buckner, Jr. on June 18, 1945, in the Battle of Okinawa during World War II.


The army is also changing its base unit from divisions to brigades. Division lineage will be retained, but the divisional headquarters will be able to command any brigade, not just brigades that carry their divisional lineage. The central part of this plan is that each brigade will be modular, i.e., all brigades of the same type will be exactly the same, and thus any brigade can be commanded by any division. As specified before the 2013 end-strength re-definitions, the three major types of ground combat brigades are:


The army employs various individual weapons to provide light firepower at short ranges. The most common weapons used by the army are the compact variant of the M16 rifle, the M4 carbine, as well as the 7.62×51mm variant of the FN SCAR for Army Rangers. The primary sidearm in the U.S. Army is the 9 mm M9 pistol; the M11 pistol is also used. Both handguns are to be replaced through the Modular Handgun System program. Soldiers are also equiped with various hand grenades, such as the M67 fragmentation grenade and M18 smoke grenade.


The army's most common vehicle is the High Mobility Multipurpose Wheeled Vehicle (HMMWV), commonly called the Humvee, which is capable of serving as a cargo/troop carrier, weapons platform, and ambulance, among many other roles. While they operate a wide variety of combat support vehicles, one of the most common types centers on the family of HEMTT vehicles. The M1A2 Abrams is the army's main battle tank, while the M2A3 Bradley is the standard infantry fighting vehicle. Other vehicles include the Stryker, and the M113 armored personnel carrier, and multiple types of Mine Resistant Ambush Protected (MRAP) vehicles.


The German states proclaimed their union as the German Empire under the Prussian king, Wilhelm I, uniting Germany as a nation-state. The Treaty of Frankfurt of 10 May 1871 gave Germany most of Alsace and some parts of Lorraine, which became the Imperial territory of Alsace-Lorraine (Reichsland Elsaß-Lothringen).The German conquest of France and the unification of Germany upset the European balance of power, that had existed since the Congress of Vienna in 1815 and Otto von Bismarck maintained great authority in international affairs for two decades. French determination to regain Alsace-Lorraine and fear of another Franco-German war, along with British apprehension about the balance of power, became factors in the causes of World War I.


The Ems telegram had exactly the effect on French public opinion that Bismarck had intended. "This text produced the effect of a red flag on the Gallic bull", Bismarck later wrote. Gramont, the French foreign minister, declared that he felt "he had just received a slap". The leader of the monarchists in Parliament, Adolphe Thiers, spoke for moderation, arguing that France had won the diplomatic battle and there was no reason for war, but he was drowned out by cries that he was a traitor and a Prussian. Napoleon's new prime minister, Emile Ollivier, declared that France had done all that it could humanly and honorably do to prevent the war, and that he accepted the responsibility "with a light heart." A crowd of 15–20,000 people, carrying flags and patriotic banners, marched through the streets of Paris, demanding war. On 19 July 1870 a declaration of war was sent to the Prussian government. The southern German states immediately sided with Prussia.


The army was still equipped with the Dreyse needle gun of Battle of Königgrätz fame, which was by this time showing the age of its 25-year-old design. The rifle had a range of only 600 m (2,000 ft) and lacked the rubber breech seal that permitted aimed shots. The deficiencies of the needle gun were more than compensated for by the famous Krupp 6-pounder (3 kg) steel breech-loading cannons being issued to Prussian artillery batteries. Firing a contact-detonated shell, the Krupp gun had a longer range and a higher rate of fire than the French bronze muzzle loading cannon, which relied on faulty time fuses.


The first action of the Franco-Prussian War took place on 4 August 1870. This battle saw the unsupported division of General Douay of I Corps, with some attached cavalry, which was posted to watch the border, attacked in overwhelming but uncoordinated fashion by the German 3rd Army. During the day, elements of a Bavarian and two Prussian corps became engaged and were aided by Prussian artillery, which blasted holes in the defenses of the town. Douay held a very strong position initially, thanks to the accurate long-range fire of the Chassepots but his force was too thinly stretched to hold it. Douay was killed in the late morning when a caisson of the divisional mitrailleuse battery exploded near him; the encirclement of the town by the Prussians threatened the French avenue of retreat.


The French were unaware of German numerical superiority at the beginning of the battle as the German 2nd Army did not attack all at once. Treating the oncoming attacks as merely skirmishes, Frossard did not request additional support from other units. By the time he realized what kind of a force he was opposing, it was too late. Seriously flawed communications between Frossard and those in reserve under Bazaine slowed down so much that by the time the reserves received orders to move out to Spicheren, German soldiers from the 1st and 2nd armies had charged up the heights. Because the reserves had not arrived, Frossard erroneously believed that he was in grave danger of being outflanked as German soldiers under General von Glume were spotted in Forbach. Instead of continuing to defend the heights, by the close of battle after dusk he retreated to the south. The German casualties were relatively high due to the advance and the effectiveness of the chassepot rifle. They were quite startled in the morning when they had found out that their efforts were not in vain—Frossard had abandoned his position on the heights.


The Battle of Gravelotte, or Gravelotte–St. Privat (18 August), was the largest battle during the Franco-Prussian War. It was fought about 6 miles (9.7 km) west of Metz, where on the previous day, having intercepted the French army's retreat to the west at the Battle of Mars-La-Tour, the Prussians were now closing in to complete the destruction of the French forces. The combined German forces, under Field Marshal Count Helmuth von Moltke, were the Prussian First and Second Armies of the North German Confederation numbering about 210 infantry battalions, 133 cavalry squadrons, and 732 heavy cannons totaling 188,332 officers and men. The French Army of the Rhine, commanded by Marshal François-Achille Bazaine, numbering about 183 infantry battalions, 104 cavalry squadrons, backed by 520 heavy cannons, totaling 112,800 officers and men, dug in along high ground with their southern left flank at the town of Rozerieulles, and their northern right flank at St. Privat.


With the defeat of Marshal Bazaine's Army of the Rhine at Gravelotte, the French were forced to retire to Metz, where they were besieged by over 150,000 Prussian troops of the First and Second Armies. Napoleon III and MacMahon formed the new French Army of Châlons, to march on to Metz to rescue Bazaine. Napoleon III personally led the army with Marshal MacMahon in attendance. The Army of Châlons marched northeast towards the Belgian border to avoid the Prussians before striking south to link up with Bazaine. The Prussians, under the command of Field Marshal Count Helmuth von Moltke, took advantage of this maneuver to catch the French in a pincer grip. He left the Prussian First and Second Armies besieging Metz, except three corps detached to form the Army of the Meuse under the Crown Prince of Saxony. With this army and the Prussian Third Army, Moltke marched northward and caught up with the French at Beaumont on 30 August. After a sharp fight in which they lost 5,000 men and 40 cannons, the French withdrew toward Sedan. Having reformed in the town, the Army of Châlons was immediately isolated by the converging Prussian armies. Napoleon III ordered the army to break out of the encirclement immediately. With MacMahon wounded on the previous day, General Auguste Ducrot took command of the French troops in the field.


When the war had begun, European public opinion heavily favored the Germans; many Italians attempted to sign up as volunteers at the Prussian embassy in Florence and a Prussian diplomat visited Giuseppe Garibaldi in Caprera. Bismarck's demand for the return of Alsace caused a dramatic shift in that sentiment in Italy, which was best exemplified by the reaction of Garibaldi soon after the revolution in Paris, who told the Movimento of Genoa on 7 September 1870 that "Yesterday I said to you: war to the death to Bonaparte. Today I say to you: rescue the French Republic by every means." Garibaldi went to France and assumed command of the Army of the Vosges, with which he operated around Dijon till the end of the war.


On 10 October, hostilities began between German and French republican forces near Orléans. At first, the Germans were victorious but the French drew reinforcements and defeated the Germans at the Battle of Coulmiers on 9 November. After the surrender of Metz, more than 100,000 well-trained and experienced German troops joined the German 'Southern Army'. The French were forced to abandon Orléans on 4 December, and were finally defeated at the Battle of Le Mans (10–12 January). A second French army which operated north of Paris was turned back at the Battle of Amiens (27 November), the Battle of Bapaume (3 January 1871) and the Battle of St. Quentin (13 January).


Although public opinion in Paris was strongly against any form of surrender or concession to the Prussians, the Government realised that it could not hold the city for much longer, and that Gambetta's provincial armies would probably never break through to relieve Paris. President Trochu resigned on 25 January and was replaced by Favre, who signed the surrender two days later at Versailles, with the armistice coming into effect at midnight. Several sources claim that in his carriage on the way back to Paris, Favre broke into tears, and collapsed into his daughter's arms as the guns around Paris fell silent at midnight. At Tours, Gambetta received word from Paris on 30 January that the Government had surrendered. Furious, he refused to surrender and launched an immediate attack on German forces at Orleans which, predictably, failed. A delegation of Parisian diplomats arrived in Tours by train on 5 February to negotiate with Gambetta, and the following day Gambetta stepped down and surrendered control of the provincial armies to the Government of National Defence, which promptly ordered a cease-fire across France.


The quick German victory over the French stunned neutral observers, many of whom had expected a French victory and most of whom had expected a long war. The strategic advantages possessed by the Germans were not appreciated outside Germany until after hostilities had ceased. Other countries quickly discerned the advantages given to the Germans by their military system, and adopted many of their innovations, particularly the General Staff, universal conscription and highly detailed mobilization systems.


The effect of these differences was accentuated by the pre-war preparations. The Prussian General Staff had drawn up minutely detailed mobilization plans using the railway system, which in turn had been partly laid out in response to recommendations of a Railway Section within the General Staff. The French railway system, with multiple competing companies, had developed purely from commercial pressures and many journeys to the front in Alsace and Lorraine involved long diversions and frequent changes between trains. Furthermore, no system had been put in place for military control of the railways, and officers simply commandeered trains as they saw fit. Rail sidings and marshalling yards became choked with loaded wagons, with nobody responsible for unloading them or directing them to the destination.


At the Battle of Mars-la-Tours, the Prussian 12th Cavalry Brigade, commanded by General Adalbert von Bredow, conducted a charge against a French artillery battery. The attack was a costly success and came to be known as "von Bredow's Death Ride", which was held to prove that cavalry charges could still prevail on the battlefield. Use of traditional cavalry on the battlefields of 1914 proved to be disastrous, due to accurate, long-range rifle fire, machine-guns and artillery. Von Bredow's attack had succeeded only because of an unusually effective artillery bombardment just before the charge, along with favorable terrain that masked his approach.


In the Prussian province of Posen, with a large Polish population, there was strong support for the French and angry demonstrations at news of Prussian-German victories—a clear manifestation of Polish nationalist feeling. Calls were also made for Polish recruits to desert from the Prussian Army—though these went mainly unheeded. An alarming report on the Posen situation, sent to Bismarck on 16 August 1870, led to the quartering of reserve troop contingents in the restive province. The Franco-Prussian War thus turned out to be a significant event also in German–Polish relations, marking the beginning of a prolonged period of repressive measures by the authorities and efforts at Germanisation.


The causes of the Franco-Prussian War are deeply rooted in the events surrounding the unification of Germany. In the aftermath of the Austro–Prussian War of 1866, Prussia had annexed numerous territories and formed the North German Confederation. This new power destabilized the European balance of power established by the Congress of Vienna in 1815 after the Napoleonic Wars. Napoleon III, then the emperor of France, demanded compensations in Belgium and on the left bank of the Rhine to secure France's strategic position, which the Prussian chancellor, Otto von Bismarck, flatly refused. Prussia then turned its attention towards the south of Germany, where it sought to incorporate the southern German kingdoms, Bavaria, Württemberg, Baden and Hesse-Darmstadt, into a unified Prussia-dominated Germany. France was strongly opposed to any further alliance of German states, which would have significantly strengthened the Prussian military.


The French Army consisted in peacetime of approximately 400,000 soldiers, some of them regulars, others conscripts who until 1869 served the comparatively long period of seven years with the colours. Some of them were veterans of previous French campaigns in the Crimean War, Algeria, the Franco-Austrian War in Italy, and in the Franco-Mexican War. However, following the "Seven Weeks War" between Prussia and Austria four years earlier, it had been calculated that the French Army could field only 288,000 men to face the Prussian Army when perhaps 1,000,000 would be required. Under Marshal Adolphe Niel, urgent reforms were made. Universal conscription (rather than by ballot, as previously) and a shorter period of service gave increased numbers of reservists, who would swell the army to a planned strength of 800,000 on mobilisation. Those who for any reason were not conscripted were to be enrolled in the Garde Mobile, a militia with a nominal strength of 400,000. However, the Franco-Prussian War broke out before these reforms could be completely implemented. The mobilisation of reservists was chaotic and resulted in large numbers of stragglers, while the Garde Mobile were generally untrained and often mutinous.


The Prussian army was controlled by the General Staff, under Field Marshal Helmuth von Moltke. The Prussian army was unique in Europe for having the only such organisation in existence, whose purpose in peacetime was to prepare the overall war strategy, and in wartime to direct operational movement and organise logistics and communications. The officers of the General Staff were hand-picked from the Prussian Kriegsakademie (War Academy). Moltke embraced new technology, particularly the railroad and telegraph, to coordinate and accelerate mobilisation of large forces.


General Frossard's II Corps and Marshal Bazaine's III Corps crossed the German border on 2 August, and began to force the Prussian 40th Regiment of the 16th Infantry Division from the town of Saarbrücken with a series of direct attacks. The Chassepot rifle proved its worth against the Dreyse rifle, with French riflemen regularly outdistancing their Prussian counterparts in the skirmishing around Saarbrücken. However the Prussians resisted strongly, and the French suffered 86 casualties to the Prussian 83 casualties. Saarbrücken also proved to be a major obstacle in terms of logistics. Only one railway there led to the German hinterland but could be easily defended by a single force, and the only river systems in the region ran along the border instead of inland. While the French hailed the invasion as the first step towards the Rhineland and later Berlin, General Le Bœuf and Napoleon III were receiving alarming reports from foreign news sources of Prussian and Bavarian armies massing to the southeast in addition to the forces to the north and northeast.


According to some historians, Bismarck adroitly created a diplomatic crisis over the succession to the Spanish throne, then edited a dispatch about a meeting between King William of Prussia and the French ambassador, to make it appear that the French had been insulted. The French press and parliament demanded a war, which the generals of Napoleon III assured him that France would win. Napoleon and his Prime Minister, Émile Ollivier, for their parts sought war to solve their problems with political disunity in France. On 16 July 1870, the French parliament voted to declare war on the German Kingdom of Prussia and hostilities began three days later. The German coalition mobilised its troops much more quickly than the French and rapidly invaded northeastern France. The German forces were superior in numbers, had better training and leadership and made more effective use of modern technology, particularly railroads and artillery.


The fighting within the town had become extremely intense, becoming a door to door battle of survival. Despite a never-ending attack of Prussian infantry, the soldiers of the 2nd Division kept to their positions. The people of the town of Wissembourg finally surrendered to the Germans. The French troops who did not surrender retreated westward, leaving behind 1,000 dead and wounded and another 1,000 prisoners and all of their remaining ammunition. The final attack by the Prussian troops also cost c. 1,000 casualties. The German cavalry then failed to pursue the French and lost touch with them. The attackers had an initial superiority of numbers, a broad deployment which made envelopment highly likely but the effectiveness of French Chassepot rifle-fire inflicted costly repulses on infantry attacks, until the French infantry had been extensively bombarded by the Prussian artillery.


The Franco-Prussian War or Franco-German War (German: Deutsch-Französischer Krieg, lit. German-French War, French: Guerre franco-allemande, lit. Franco-German War), often referred to in France as the War of 1870 (19 July 1870 – 10 May 1871), was a conflict between the Second French Empire and the German states of the North German Confederation led by the Kingdom of Prussia. The conflict was caused by Prussian ambitions to extend German unification. Some historians argue that the Prussian chancellor Otto von Bismarck planned to provoke a French attack in order to draw the southern German states—Baden, Württemberg, Bavaria and Hesse-Darmstadt—into an alliance with the North German Confederation dominated by Prussia, while others contend that Bismarck did not plan anything and merely exploited the circumstances as they unfolded.


The immediate cause of the war resided in the candidacy of a Leopold of Hohenzollern-Sigmaringen, a Prussian prince, to the throne of Spain. France feared encirclement by an alliance between Prussia and Spain. The Hohenzollern prince's candidacy was withdrawn under French diplomatic pressure, but Otto von Bismarck goaded the French into declaring war by altering a telegram sent by William I. Releasing the Ems Dispatch to the public, Bismarck made it sound as if the king had treated the French envoy in a demeaning fashion, which inflamed public opinion in France.


The Battle of Wörth (also known as Fröschwiller or Reichshoffen) began when the two armies clashed again on 6 August near Wörth in the town of Fröschwiller, about 10 miles (16 km) from Wissembourg. The Crown Prince of Prussia's 3rd army had, on the quick reaction of his Chief of Staff General von Blumenthal, drawn reinforcements which brought its strength up to 140,000 troops. The French had been slowly reinforced and their force numbered only 35,000. Although badly outnumbered, the French defended their position just outside Fröschwiller. By afternoon, the Germans had suffered c. 10,500 killed or wounded and the French had lost a similar number of casualties and another c. 9,200 men taken prisoner, a loss of about 50%. The Germans captured Fröschwiller which sat on a hilltop in the centre of the French line. Having lost any hope for victory and facing a massacre, the French army disengaged and retreated in a westerly direction towards Bitche and Saverne, hoping to join French forces on the other side of the Vosges mountains. The German 3rd army did not pursue the French but remained in Alsace and moved slowly south, attacking and destroying the French garrisons in the vicinity.


In Prussia, some officials considered a war against France both inevitable and necessary to arouse German nationalism in those states that would allow the unification of a great German empire. This aim was epitomized by Prussian Chancellor Otto von Bismarck's later statement: "I did not doubt that a Franco-German war must take place before the construction of a United Germany could be realised." Bismarck also knew that France should be the aggressor in the conflict to bring the southern German states to side with Prussia, hence giving Germans numerical superiority. Many Germans also viewed the French as the traditional destabilizer of Europe, and sought to weaken France to prevent further breaches of the peace.


On 18 August, the battle began when at 08:00 Moltke ordered the First and Second Armies to advance against the French positions. By 12:00, General Manstein opened up the battle before the village of Amanvillers with artillery from the 25th Infantry Division. But the French had spent the night and early morning digging trenches and rifle pits while placing their artillery and their mitrailleuses in concealed positions. Finally aware of the Prussian advance, the French opened up a massive return fire against the mass of advancing Germans. The battle at first appeared to favor the French with their superior Chassepot rifle. However, the Prussian artillery was superior with the all-steel Krupp breech-loading gun. By 14:30, General Steinmetz, the commander of the First Army, unilaterally launched his VIII Corps across the Mance Ravine in which the Prussian infantry were soon pinned down by murderous rifle and mitrailleuse fire from the French positions. At 15:00, the massed guns of the VII and VIII Corps opened fire to support the attack. But by 16:00, with the attack in danger of stalling, Steinmetz ordered the VII Corps forward, followed by the 1st Cavalry Division.


French infantry were equipped with the breech-loading Chassepot rifle, one of the most modern mass-produced firearms in the world at the time. With a rubber ring seal and a smaller bullet, the Chassepot had a maximum effective range of some 1,500 metres (4,900 ft) with a short reloading time. French tactics emphasised the defensive use of the Chassepot rifle in trench-warfare style fighting—the so-called feu de bataillon. The artillery was equipped with rifled, muzzle-loaded La Hitte guns. The army also possessed a precursor to the machine-gun: the mitrailleuse, which could unleash significant, concentrated firepower but nevertheless lacked range and was comparatively immobile, and thus prone to being easily overrun. The mitrailleuse was mounted on an artillery gun carriage and grouped in batteries in a similar fashion to cannon.


On 1 September 1870, the battle opened with the Army of Châlons, with 202 infantry battalions, 80 cavalry squadrons and 564 guns, attacking the surrounding Prussian Third and Meuse Armies totaling 222 infantry battalions, 186 cavalry squadrons and 774 guns. General De Wimpffen, the commander of the French V Corps in reserve, hoped to launch a combined infantry and cavalry attack against the Prussian XI Corps. But by 11:00, Prussian artillery took a toll on the French while more Prussian troops arrived on the battlefield. The French cavalry, commanded by General Marguerite, launched three desperate attacks on the nearby village of Floing where the Prussian XI Corps was concentrated. Marguerite was killed leading the very first charge and the two additional charges led to nothing but heavy losses. By the end of the day, with no hope of breaking out, Napoleon III called off the attacks. The French lost over 17,000 men, killed or wounded, with 21,000 captured. The Prussians reported their losses at 2,320 killed, 5,980 wounded and 700 captured or missing. By the next day, on 2 September, Napoleon III surrendered and was taken prisoner with 104,000 of his soldiers. It was an overwhelming victory for the Prussians, for they not only captured an entire French army, but the leader of France as well. The defeat of the French at Sedan had decided the war in Prussia's favour. One French army was now immobilised and besieged in the city of Metz, and no other forces stood on French ground to prevent a German invasion. Nevertheless, the war would continue.


A pre-war plan laid out by the late Marshal Niel called for a strong French offensive from Thionville towards Trier and into the Prussian Rhineland. This plan was discarded in favour of a defensive plan by Generals Charles Frossard and Bartélemy Lebrun, which called for the Army of the Rhine to remain in a defensive posture near the German border and repel any Prussian offensive. As Austria along with Bavaria, Württemberg and Baden were expected to join in a revenge war against Prussia, I Corps would invade the Bavarian Palatinate and proceed to "free" the South German states in concert with Austro-Hungarian forces. VI Corps would reinforce either army as needed.


On the French side, planning after the disaster at Wissembourg had become essential. General Le Bœuf, flushed with anger, was intent upon going on the offensive over the Saar and countering their loss. However, planning for the next encounter was more based upon the reality of unfolding events rather than emotion or pride, as Intendant General Wolff told him and his staff that supply beyond the Saar would be impossible. Therefore, the armies of France would take up a defensive position that would protect against every possible attack point, but also left the armies unable to support each other.


Following the Army of the Loire's defeats, Gambetta turned to General Faidherbe's Army of the North. The army had achieved several small victories at towns such as Ham, La Hallue, and Amiens and was protected by the belt of fortresses in northern France, allowing Faidherbe's men to launch quick attacks against isolated Prussian units, then retreat behind the fortresses. Despite access to the armaments factories of Lille, the Army of the North suffered from severe supply difficulties, which depressed morale. In January 1871, Gambetta forced Faidherbe to march his army beyond the fortresses and engage the Prussians in open battle. The army was severely weakened by low morale, supply problems, the terrible winter weather and low troop quality, whilst general Faidherbe was unable to command due to his poor health, the result of decades of campaigning in West Africa. At the Battle of St. Quentin, the Army of the North suffered a crushing defeat and was scattered, releasing thousands of Prussian soldiers to be relocated to the East.


Despite odds of four to one, the III Corps launched a risky attack. The French were routed and the III Corps captured Vionville, blocking any further escape attempts to the west. Once blocked from retreat, the French in the fortress of Metz had no choice but to engage in a fight that would see the last major cavalry engagement in Western Europe. The battle soon erupted, and III Corps was shattered by incessant cavalry charges, losing over half its soldiers. The German Official History recorded 15,780 casualties and French casualties of 13,761 men.


With the defeat of the First Army, Prince Frederick Charles ordered a massed artillery attack against Canrobert's position at St. Privat to prevent the Guards attack from failing too. At 19:00 the 3rd Division of Fransecky's II Corps of the Second Army advanced across Ravine while the XII Corps cleared out the nearby town of Roncourt and with the survivors of the 1st Guards Infantry Division launched a fresh attack against the ruins of St. Privat. At 20:00, the arrival of the Prussian 4th Infantry Division of the II Corps and with the Prussian right flank on Mance Ravine, the line stabilised. By then, the Prussians of the 1st Guards Infantry Division and the XII and II Corps captured St. Privat forcing the decimated French forces to withdraw. With the Prussians exhausted from the fighting, the French were now able to mount a counter-attack. General Bourbaki, however, refused to commit the reserves of the French Old Guard to the battle because, by that time, he considered the overall situation a 'defeat'. By 22:00, firing largely died down across the battlefield for the night. The next morning, the French Army of the Rhine, rather than resume the battle with an attack of its own against the battle-weary German armies, retreated to Metz where they were besieged and forced to surrender two months later.


When the war began, the French government ordered a blockade of the North German coasts, which the small North German navy (Norddeutsche Bundesmarine) with only five ironclads could do little to oppose. For most of the war, the three largest German ironclads were out of service with engine troubles; only the turret ship SMS Arminius was available to conduct operations. By the time engine repairs had been completed, the French fleet had already departed. The blockade proved only partially successful due to crucial oversights by the planners in Paris. Reservists that were supposed to be at the ready in case of war, were working in the Newfoundland fisheries or in Scotland. Only part of the 470-ship French Navy put to sea on 24 July. Before long, the French navy ran short of coal, needing 200 short tons (180 t) per day and having a bunker capacity in the fleet of only 250 short tons (230 t). A blockade of Wilhelmshaven failed and conflicting orders about operations in the Baltic Sea or a return to France, made the French naval efforts futile. Spotting a blockade-runner became unwelcome because of the question du charbon; pursuit of Prussian ships quickly depleted the coal reserves of the French ships.


The Battle of Spicheren, on 5 August, was the second of three critical French defeats. Moltke had originally planned to keep Bazaine's army on the Saar River until he could attack it with the 2nd Army in front and the 1st Army on its left flank, while the 3rd Army closed towards the rear. The aging General von Steinmetz made an overzealous, unplanned move, leading the 1st Army south from his position on the Moselle. He moved straight toward the town of Spicheren, cutting off Prince Frederick Charles from his forward cavalry units in the process.


The Prussian General Staff developed by Moltke proved to be extremely effective, in contrast to the traditional French school. This was in large part due to the fact that the Prussian General Staff was created to study previous Prussian operations and learn to avoid mistakes. The structure also greatly strengthened Moltke's ability to control large formations spread out over significant distances. The Chief of the General Staff, effectively the commander in chief of the Prussian army, was independent of the minister of war and answered only to the monarch. The French General Staff—along with those of every other European military—was little better than a collection of assistants for the line commanders. This disorganization hampered the French commanders' ability to exercise control of their forces.


The Germans expected to negotiate an end to the war but immediately ordered an advance on Paris; by 15 September Moltke issued the orders for an investment of Paris and on 20 September the encirclement was complete. Bismarck met Favre on 18 September at the Château de Ferrières and demanded a frontier immune to a French war of revenge, which included Strasbourg, Alsace and most the Moselle department in Lorraine of which Metz was the capital. In return for an armistice for the French to elect a National Assembly, Bismarck demanded the surrender of Strasbourg and the fortress city of Toul. To allow supplies into Paris, one of the perimeter forts had to be handed over. Favre was unaware that the real aim of Bismarck in making such extortionate demands was to establish a durable peace on the new western frontier of Germany, preferably by a peace with a friendly government, on terms acceptable to French public opinion. An impregnable military frontier was an inferior alternative to him, favoured only by the militant nationalists on the German side.


By 16:50, with the Prussian southern attacks in danger of breaking up, the Prussian 3rd Guards Infantry Brigade of the Second Army opened an attack against the French positions at St. Privat which were commanded by General Canrobert. At 17:15, the Prussian 4th Guards Infantry Brigade joined the advance followed at 17:45 by the Prussian 1st Guards Infantry Brigade. All of the Prussian Guard attacks were pinned down by lethal French gunfire from the rifle pits and trenches. At 18:15 the Prussian 2nd Guards Infantry Brigade, the last of the 1st Guards Infantry Division, was committed to the attack on St. Privat while Steinmetz committed the last of the reserves of the First Army across the Mance Ravine. By 18:30, a considerable portion of the VII and VIII Corps disengaged from the fighting and withdrew towards the Prussian positions at Rezonville.


The Prussian Army, under the terms of the armistice, held a brief victory parade in Paris on 17 February; the city was silent and draped with black and the Germans quickly withdrew. Bismarck honoured the armistice, by allowing train loads of food into Paris and withdrawing Prussian forces to the east of the city, prior to a full withdrawal once France agreed to pay a five billion franc war indemnity. At the same time, Prussian forces were concentrated in the provinces of Alsace and Lorraine. An exodus occurred from Paris as some 200,000 people, predominantly middle-class, went to the countryside.


When the news arrived at Paris of the surrender at Sedan of Napoleon III and 80,000 men, the Second Empire was overthrown by a popular uprising in Paris, which forced the proclamation of a Provisional Government and a Third Republic by general Trochu, Favre and Gambetta at Paris on 4 September, the new government calling itself the Government of National Defence. After the German victory at Sedan, most of the French standing army was either besieged in Metz or prisoner of the Germans, who hoped for an armistice and an end to the war. Bismarck wanted an early peace but had difficulty in finding a legitimate French authority with which to negotiate. The Government of National Defence had no electoral mandate, the Emperor was a captive and the Empress in exile but there had been no abdication de jure and the army was still bound by an oath of allegiance to the defunct imperial régime.


A series of swift Prussian and German victories in eastern France, culminating in the Siege of Metz and the Battle of Sedan, saw the army of the Second Empire decisively defeated (Napoleon III had been captured at Sedan on 2 September). A Government of National Defence declared the Third Republic in Paris on 4 September and continued the war and for another five months, the German forces fought and defeated new French armies in northern France. Following the Siege of Paris, the capital fell on 28 January 1871 and then a revolutionary uprising called the Paris Commune seized power in the capital and held it for two months, until it was bloodily suppressed by the regular French army at the end of May 1871.


Some historians argue that Napoleon III also sought war, particularly for the diplomatic defeat in 1866 in leveraging any benefits from the Austro-Prussian War, and he believed he would win a conflict with Prussia. They also argue that he wanted a war to resolve growing domestic political problems. Other historians, notably French historian Pierre Milza, dispute this. On 8 May 1870, shortly before the war, French voters had overwhelmingly supported Napoleon III's program in a national plebiscite, with 7,358,000 votes yes against 1,582,000 votes no, an increase of support of two million votes since the legislative elections in 1869. According to Milza, the Emperor had no need for a war to increase his popularity.


To relieve pressure from the expected German attack into Alsace-Lorraine, Napoleon III and the French high command planned a seaborne invasion of northern Germany as soon as war began. The French expected the invasion to divert German troops and to encourage Denmark to join in the war, with its 50,000-strong army and the Royal Danish Navy. It was discovered that Prussia had recently built defences around the big North German ports, including coastal artillery batteries with Krupp heavy artillery, which with a range of 4,000 yards (3,700 m), had double the range of French naval guns. The French Navy lacked the heavy guns to engage the coastal defences and the topography of the Prussian coast made a seaborne invasion of northern Germany impossible.


The Prussian Army was composed not of regulars but conscripts. Service was compulsory for all of men of military age, and thus Prussia and its North and South German allies could mobilise and field some 1,000,000 soldiers in time of war. German tactics emphasised encirclement battles like Cannae and using artillery offensively whenever possible. Rather than advancing in a column or line formation, Prussian infantry moved in small groups that were harder to target by artillery or French defensive fire. The sheer number of soldiers available made encirclement en masse and destruction of French formations relatively easy.


In addition, the Prussian military education system was superior to the French model; Prussian staff officers were trained to exhibit initiative and independent thinking. Indeed, this was Moltke's expectation. The French, meanwhile, suffered from an education and promotion system that stifled intellectual development. According to the military historian Dallas Irvine, the system "was almost completely effective in excluding the army's brain power from the staff and high command. To the resulting lack of intelligence at the top can be ascribed all the inexcusable defects of French military policy."


The French breech-loading rifle, the Chassepot, had a far longer range than the German needle gun; 1,500 yards (1,400 m) compared to 600 yd (550 m). The French also had an early machine-gun type weapon, the mitrailleuse, which could fire its thirty-seven barrels at a range of around 1,200 yd (1,100 m). It was developed in such secrecy, that little training with the weapon had occurred, leaving French gunners with no experience; the gun was treated like artillery and in this role it was ineffective. Worse still, once the small number of soldiers who had been trained how to use the new weapon became casualties, there were no replacements who knew how to operate the mitrailleuse.


The French Marines and naval infantry intended for the invasion of northern Germany were dispatched to reinforce the French Army of Châlons and fell into captivity at Sedan along with Napoleon III. A shortage of officers, following the capture of most of the professional French army at the Siege of Metz and at the Battle of Sedan, led naval officers to be sent from their ships to command hastily assembled reservists of the Garde Mobile. As the autumn storms of the North Sea forced the return of more of the French ships, the blockade of the north German ports diminished and in September 1870 the French navy abandoned the blockade for the winter. The rest of the navy retired to ports along the English Channel and remained in port for the rest of the war.


Marshal MacMahon, now closest to Wissembourg, spread his four divisions over 20 miles (32 km) to react to any Prussian invasion. This organization of forces was due to a lack of supplies, forcing each division to seek out basic provisions along with the representatives of the army supply arm that was supposed to aid them. What made a bad situation much worse was the conduct of General Auguste-Alexandre Ducrot, commander of the 1st Division. He told General Abel Douay, commander of the 2nd Division, on 1 August that "The information I have received makes me suppose that the enemy has no considerable forces very near his advance posts, and has no desire to take the offensive". Two days later, he told MacMahon that he had not found "a single enemy post ... it looks to me as if the menace of the Bavarians is simply bluff". Even though Ducrot shrugged off the possibility of an attack by the Germans, MacMahon tried to warn the other divisions of his army, without success.


During the war, the Paris National Guard, particularly in the working-class neighbourhoods of Paris, had become highly politicised and units elected officers; many refused to wear uniforms or obey commands from the national government. National guard units tried to seize power in Paris on 31 October 1870 and 22 January 1871. On 18 March 1871, when the regular army tried to remove cannons from an artillery park on Montmartre, National Guard units resisted and killed two army generals. The national government and regular army forces retreated to Versailles and a revolutionary government was proclaimed in Paris. A Commune was elected, which was dominated by socialists, anarchists and revolutionaries. The red flag replaced the French tricolour and a civil war began between the Commune and the regular army, which attacked and recaptured Paris from 21–28 May in La Semaine Sanglante (Bloody week).


While the French army under General MacMahon engaged the German 3rd Army at the Battle of Wörth, the German 1st Army under Steinmetz finished their advance west from Saarbrücken. A patrol from the German 2nd Army under Prince Friedrich Karl of Prussia spotted decoy fires close and Frossard's army farther off on a distant plateau south of the town of Spicheren, and took this as a sign of Frossard's retreat. Ignoring Moltke's plan again, both German armies attacked Frossard's French 2nd Corps, fortified between Spicheren and Forbach.


The casualties were horrible, especially for the attacking Prussian forces. A grand total of 20,163 German troops were killed, wounded or missing in action during the August 18 battle. The French losses were 7,855 killed and wounded along with 4,420 prisoners of war (half of them were wounded) for a total of 12,275. While most of the Prussians fell under the French Chassepot rifles, most French fell under the Prussian Krupp shells. In a breakdown of the casualties, Frossard's II Corps of the Army of the Rhine suffered 621 casualties while inflicting 4,300 casualties on the Prussian First Army under Steinmetz before the Pointe du Jour. The Prussian Guards Infantry Divisions losses were even more staggering with 8,000 casualties out of 18,000 men. The Special Guards Jäger lost 19 officers, a surgeon and 431 men out of a total of 700. The 2nd Guards Infantry Brigade lost 39 officers and 1,076 men. The 3rd Guards Infantry Brigade lost 36 officers and 1,060 men. On the French side, the units holding St. Privat lost more than half their number in the village.


While the republican government was amenable to war reparations or ceding colonial territories in Africa or in South East Asia to Prussia, Favre on behalf of the Government of National Defense, declared on 6 September that France would not "yield an inch of its territory nor a stone of its fortresses." The republic then renewed the declaration of war, called for recruits in all parts of the country and pledged to drive the German troops out of France by a guerre à outrance. Under these circumstances, the Germans had to continue the war, yet could not pin down any proper military opposition in their vicinity. As the bulk of the remaining French armies were digging-in near Paris, the German leaders decided to put pressure upon the enemy by attacking Paris. By September 15, German troops reached the outskirts of the fortified city. On September 19, the Germans surrounded it and erected a blockade, as already established at Metz.


Albrecht von Roon, the Prussian Minister of War from 1859 to 1873, put into effect a series of reforms of the Prussian military system in the 1860s. Among these were two major reforms that substantially increased the military power of Germany. The first was a reorganization of the army that integrated the regular army and the Landwehr reserves. The second was the provision for the conscription of every male Prussian of military age in the event of mobilization. Thus, despite the population of France being greater than the population of all of the German states that participated in the war, the Germans mobilized more soldiers for battle.


The French were equipped with bronze, rifled muzzle-loading artillery, while the Prussians used new steel breech-loading guns, which had a far longer range and a faster rate of fire. Prussian gunners strove for a high rate of fire, which was discouraged in the French army in the belief that it wasted ammunition. In addition, the Prussian artillery batteries had 30% more guns than their French counterparts. The Prussian guns typically opened fire at a range of 2–3 kilometres (1.2–1.9 mi), beyond the range of French artillery or the Chassepot rifle. The Prussian batteries could thus destroy French artillery with impunity, before being moved forward to directly support infantry attacks.


On 28 January 1871 the Government of National Defence based in Paris negotiated an armistice with the Prussians. With Paris starving, and Gambetta's provincial armies reeling from one disaster after another, French foreign minister Favre went to Versailles on 24 January to discuss peace terms with Bismarck. Bismarck agreed to end the siege and allow food convoys to immediately enter Paris (including trains carrying millions of German army rations), on condition that the Government of National Defence surrender several key fortresses outside Paris to the Prussians. Without the forts, the French Army would no longer be able to defend Paris.


During the fighting, the Communards killed c. 500 people, including the Archbishop of Paris, and burned down many government buildings, including the Tuileries Palace and the Hotel de Ville. Communards captured with weapons were routinely shot by the army and Government troops killed from 7,000–30,000 Communards in the fighting and in massacres of men, women, and children during and after the Commune. More recent histories, based on studies of the number buried in Paris cemeteries and in mass graves after the fall of the Commune, put the number killed at between 6,000 and 10,000. Twenty-six courts were established to try more than 40,000 people who had been arrested, which took until 1875 and imposed 95 death sentences, of which 23 were inflicted. Forced labour for life was imposed on 251 people, 1,160 people were transported to "a fortified place" and 3,417 people were transported. About 20,000 Communards were held in prison hulks until released in 1872 and a great many Communards fled abroad to England, Switzerland, Belgium or the United States. The survivors were amnestied by a bill introduced by Gambetta in 1880 and allowed to return.


At the outset of the Franco-Prussian War, 462,000 German soldiers concentrated on the French frontier while only 270,000 French soldiers could be moved to face them, the French army having lost 100,000 stragglers before a shot was fired through poor planning and administration. This was partly due to the peacetime organisations of the armies. Each Prussian Corps was based within a Kreis (literally "circle") around the chief city in an area. Reservists rarely lived more than a day's travel from their regiment's depot. By contrast, French regiments generally served far from their depots, which in turn were not in the areas of France from which their soldiers were drawn. Reservists often faced several days' journey to report to their depots, and then another long journey to join their regiments. Large numbers of reservists choked railway stations, vainly seeking rations and orders.


The events of the Franco-Prussian War had great influence on military thinking over the next forty years. Lessons drawn from the war included the need for a general staff system, the scale and duration of future wars and the tactical use of artillery and cavalry. The bold use of artillery by the Prussians, to silence French guns at long range and then to directly support infantry attacks at close range, proved to be superior to the defensive doctrine employed by French gunners. The Prussian tactics were adopted by European armies by 1914, exemplified in the French 75, an artillery piece optimised to provide direct fire support to advancing infantry. Most European armies ignored the evidence of the Russo-Japanese War of 1904–05 which suggested that infantry armed with new smokeless-powder rifles could engage gun crews effectively. This forced gunners to fire at longer range using indirect fire, usually from a position of cover.


The creation of a unified German Empire ended the balance of power that had been created with the Congress of Vienna after the end of the Napoleonic Wars. Germany had established itself as the main power in continental Europe with the most powerful and professional army in the world.[citation needed] Although Great Britain remained the dominant world power, British involvement in European affairs during the late 19th century was very limited, allowing Germany to exercise great influence over the European mainland.[citation needed] Besides, the Crown Prince's marriage with the daughter of Queen Victoria was only the most prominent of several German–British relationships.


Puberty occurs through a long process and begins with a surge in hormone production, which in turn causes a number of physical changes. It is the stage of life characterized by the appearance and development of secondary sex characteristics (for example, a deeper voice and larger adam's apple in boys, and development of breasts and more curved and prominent hips in girls) and a strong shift in hormonal balance towards an adult state. This is triggered by the pituitary gland, which secretes a surge of hormonal agents into the blood stream, initiating a chain reaction to occur. The male and female gonads are subsequently activated, which puts them into a state of rapid growth and development; the triggered gonads now commence the mass production of the necessary chemicals. The testes primarily release testosterone, and the ovaries predominantly dispense estrogen. The production of these hormones increases gradually until sexual maturation is met. Some boys may develop gynecomastia due to an imbalance of sex hormones, tissue responsiveness or obesity.


A thorough understanding of adolescence in society depends on information from various perspectives, including psychology, biology, history, sociology, education, and anthropology. Within all of these perspectives, adolescence is viewed as a transitional period between childhood and adulthood, whose cultural purpose is the preparation of children for adult roles. It is a period of multiple transitions involving education, training, employment and unemployment, as well as transitions from one living circumstance to another.


Pubertal development also affects circulatory and respiratory systems as an adolescents' heart and lungs increase in both size and capacity. These changes lead to increased strength and tolerance for exercise. Sex differences are apparent as males tend to develop "larger hearts and lungs, higher systolic blood pressure, a lower resting heart rate, a greater capacity for carrying oxygen to the blood, a greater power for neutralizing the chemical products of muscular exercise, higher blood hemoglobin and more red blood cells".


The human brain is not fully developed by the time a person reaches puberty. Between the ages of 10 and 25, the brain undergoes changes that have important implications for behavior (see Cognitive development below). The brain reaches 90% of its adult size by the time a person is six years of age. Thus, the brain does not grow in size much during adolescence. However, the creases in the brain continue to become more complex until the late teens. The biggest changes in the folds of the brain during this time occur in the parts of the cortex that process cognitive and emotional information.


Serotonin is a neuromodulator involved in regulation of mood and behavior. Development in the limbic system plays an important role in determining rewards and punishments and processing emotional experience and social information. Changes in the levels of the neurotransmitters dopamine and serotonin in the limbic system make adolescents more emotional and more responsive to rewards and stress. The corresponding increase in emotional variability also can increase adolescents' vulnerability. The effect of serotonin is not limited to the limbic system: Several serotonin receptors have their gene expression change dramatically during adolescence, particularly in the human frontal and prefrontal cortex .


Adolescents' thinking is less bound to concrete events than that of children: they can contemplate possibilities outside the realm of what currently exists. One manifestation of the adolescent's increased facility with thinking about possibilities is the improvement of skill in deductive reasoning, which leads to the development of hypothetical thinking. This provides the ability to plan ahead, see the future consequences of an action and to provide alternative explanations of events. It also makes adolescents more skilled debaters, as they can reason against a friend's or parent's assumptions. Adolescents also develop a more sophisticated understanding of probability.


The timing of puberty can have important psychological and social consequences. Early maturing boys are usually taller and stronger than their friends. They have the advantage in capturing the attention of potential partners and in becoming hand-picked for sports. Pubescent boys often tend to have a good body image, are more confident, secure, and more independent. Late maturing boys can be less confident because of poor body image when comparing themselves to already developed friends and peers. However, early puberty is not always positive for boys; early sexual maturation in boys can be accompanied by increased aggressiveness due to the surge of hormones that affect them. Because they appear older than their peers, pubescent boys may face increased social pressure to conform to adult norms; society may view them as more emotionally advanced, despite the fact that their cognitive and social development may lag behind their appearance. Studies have shown that early maturing boys are more likely to be sexually active and are more likely to participate in risky behaviors.


Wisdom, or the capacity for insight and judgment that is developed through experience, increases between the ages of fourteen and twenty-five, then levels off. Thus, it is during the adolescence-adulthood transition that individuals acquire the type of wisdom that is associated with age. Wisdom is not the same as intelligence: adolescents do not improve substantially on IQ tests since their scores are relative to others in their same age group, and relative standing usually does not change—everyone matures at approximately the same rate in this way.


In studying adolescent development, adolescence can be defined biologically, as the physical transition marked by the onset of puberty and the termination of physical growth; cognitively, as changes in the ability to think abstractly and multi-dimensionally; or socially, as a period of preparation for adult roles. Major pubertal and biological changes include changes to the sex organs, height, weight, and muscle mass, as well as major changes in brain structure and organization. Cognitive advances encompass both increases in knowledge and in the ability to think abstractly and to reason more effectively. The study of adolescent development often involves interdisciplinary collaborations. For example, researchers in neuroscience or bio-behavioral health might focus on pubertal changes in brain structure and its effects on cognition or social relations. Sociologists interested in adolescence might focus on the acquisition of social roles (e.g., worker or romantic partner) and how this varies across cultures or social conditions. Developmental psychologists might focus on changes in relations with parents and peers as a function of school structure and pubertal status.


Jean Macfarlane founded the University of California, Berkeley's Institute of Human Development, formerly called the Institute of Child Welfare, in 1927. The Institute was instrumental in initiating studies of healthy development, in contrast to previous work that had been dominated by theories based on pathological personalities. The studies looked at human development during the Great Depression and World War II, unique historical circumstances under which a generation of children grew up. The Oakland Growth Study, initiated by Harold Jones and Herbert Stolz in 1931, aimed to study the physical, intellectual, and social development of children in the Oakland area. Data collection began in 1932 and continued until 1981, allowing the researchers to gather longitudinal data on the individuals that extended past adolescence into adulthood. Jean Macfarlane launched the Berkeley Guidance Study, which examined the development of children in terms of their socioeconomic and family backgrounds. These studies provided the background for Glen Elder in the 1960s, to propose a life-course perspective of adolescent development. Elder formulated several descriptive principles of adolescent development. The principle of historical time and place states that an individual's development is shaped by the period and location in which they grow up. The principle of the importance of timing in one's life refers to the different impact that life events have on development based on when in one's life they occur. The idea of linked lives states that one's development is shaped by the interconnected network of relationships of which one is a part; and the principle of human agency asserts that one's life course is constructed via the choices and actions of an individual within the context of their historical period and social network.


The major landmark of puberty for males is the first ejaculation, which occurs, on average, at age 13. For females, it is menarche, the onset of menstruation, which occurs, on average, between ages 12 and 13. The age of menarche is influenced by heredity, but a girl's diet and lifestyle contribute as well. Regardless of genes, a girl must have a certain proportion of body fat to attain menarche. Consequently, girls who have a high-fat diet and who are not physically active begin menstruating earlier, on average, than girls whose diet contains less fat and whose activities involve fat reducing exercise (e.g. ballet and gymnastics). Girls who experience malnutrition or are in societies in which children are expected to perform physical labor also begin menstruating at later ages.


Adolescents can conceptualize multiple "possible selves" that they could become and long-term possibilities and consequences of their choices. Exploring these possibilities may result in abrupt changes in self-presentation as the adolescent chooses or rejects qualities and behaviors, trying to guide the actual self toward the ideal self (who the adolescent wishes to be) and away from the feared self (who the adolescent does not want to be). For many, these distinctions are uncomfortable, but they also appear to motivate achievement through behavior consistent with the ideal and distinct from the feared possible selves.


In females, changes in the primary sex characteristics involve growth of the uterus, vagina, and other aspects of the reproductive system. Menarche, the beginning of menstruation, is a relatively late development which follows a long series of hormonal changes. Generally, a girl is not fully fertile until several years after menarche, as regular ovulation follows menarche by about two years. Unlike males, therefore, females usually appear physically mature before they are capable of becoming pregnant.


Primary sex characteristics are those directly related to the sex organs. In males, the first stages of puberty involve growth of the testes and scrotum, followed by growth of the penis. At the time that the penis develops, the seminal vesicles, the prostate, and the bulbourethral gland also enlarge and develop. The first ejaculation of seminal fluid generally occurs about one year after the beginning of accelerated penis growth, although this is often determined culturally rather than biologically, since for many boys first ejaculation occurs as a result of masturbation. Boys are generally fertile before they have an adult appearance.


Adolescence marks a rapid change in one's role within a family. Young children tend to assert themselves forcefully, but are unable to demonstrate much influence over family decisions until early adolescence, when they are increasingly viewed by parents as equals. The adolescent faces the task of increasing independence while preserving a caring relationship with his or her parents. When children go through puberty, there is often a significant increase in parent–child conflict and a less cohesive familial bond. Arguments often concern minor issues of control, such as curfew, acceptable clothing, and the adolescent's right to privacy, which adolescents may have previously viewed as issues over which their parents had complete authority. Parent-adolescent disagreement also increases as friends demonstrate a greater impact on one another, new influences on the adolescent that may be in opposition to parents' values. Social media has also played an increasing role in adolescent and parent disagreements. While parents never had to worry about the threats of social media in the past, it has become a dangerous place for children. While adolescents strive for their freedoms, the unknowns to parents of what their child is doing on social media sites is a challenging subject, due to the increasing amount of predators on social media sites. Many parents have very little knowledge of social networking sites in the first place and this further increases their mistrust. An important challenge for the parent–adolescent relationship is to understand how to enhance the opportunities of online communication while managing its risks. Although conflicts between children and parents increase during adolescence, these are just relatively minor issues. Regarding their important life issues, most adolescents still share the same attitudes and values as their parents.


The first areas of the brain to be pruned are those involving primary functions, such as motor and sensory areas. The areas of the brain involved in more complex processes lose matter later in development. These include the lateral and prefrontal cortices, among other regions. Some of the most developmentally significant changes in the brain occur in the prefrontal cortex, which is involved in decision making and cognitive control, as well as other higher cognitive functions. During adolescence, myelination and synaptic pruning in the prefrontal cortex increases, improving the efficiency of information processing, and neural connections between the prefrontal cortex and other regions of the brain are strengthened. This leads to better evaluation of risks and rewards, as well as improved control over impulses. Specifically, developments in the dorsolateral prefrontal cortex are important for controlling impulses and planning ahead, while development in the ventromedial prefrontal cortex is important for decision making. Changes in the orbitofrontal cortex are important for evaluating rewards and risks.


Communication within peer groups allows adolescents to explore their feelings and identity as well as develop and evaluate their social skills. Peer groups offer members the opportunity to develop social skills such as empathy, sharing, and leadership. Adolescents choose peer groups based on characteristics similarly found in themselves. By utilizing these relationships, adolescents become more accepting of who they are becoming. Group norms and values are incorporated into an adolescent’s own self-concept. Through developing new communication skills and reflecting upon those of their peers, as well as self-opinions and values, an adolescent can share and express emotions and other concerns without fear of rejection or judgment. Peer groups can have positive influences on an individual, such as on academic motivation and performance. However, while peers may facilitate social development for one another they may also hinder it. Peers can have negative influences, such as encouraging experimentation with drugs, drinking, vandalism, and stealing through peer pressure. Susceptibility to peer pressure increases during early adolescence, peaks around age 14, and declines thereafter. Further evidence of peers hindering social development has been found in Spanish teenagers, where emotional (rather than solution-based) reactions to problems and emotional instability have been linked with physical aggression against peers. Both physical and relational aggression are linked to a vast number of enduring psychological difficulties, especially depression, as is social rejection. Because of this, bullied adolescents often develop problems that lead to further victimization. Bullied adolescents are both more likely to continued to be bullied and to bully others in the future. However, this relationship is less stable in cases of cyberbullying, a relatively new issue among adolescents.


There are at least two major approaches to understanding cognitive change during adolescence. One is the constructivist view of cognitive development. Based on the work of Piaget, it takes a quantitative, state-theory approach, hypothesizing that adolescents' cognitive improvement is relatively sudden and drastic. The second is the information-processing perspective, which derives from the study of artificial intelligence and attempts to explain cognitive development in terms of the growth of specific components of the thinking process.


Adolescence marks a time of sexual maturation, which manifests in social interactions as well. While adolescents may engage in casual sexual encounters (often referred to as hookups), most sexual experience during this period of development takes place within romantic relationships. Adolescents can use technologies and social media to seek out romantic relationships as they feel it is a safe place to try out dating and identity exploration. From these social media encounters, a further relationship may begin. Kissing, hand holding, and hugging signify satisfaction and commitment. Among young adolescents, "heavy" sexual activity, marked by genital stimulation, is often associated with violence, depression, and poor relationship quality. This effect does not hold true for sexual activity in late adolescence that takes place within a romantic relationship. Some research suggest that there are genetic causes of early sexual activity that are also risk factors for delinquency, suggesting that there is a group who are at risk for both early sexual activity and emotional distress. For old adolescents, though, sexual activity in the context of romantic relationships was actually correlated with lower levels of deviant behavior after controlling for genetic risks, as opposed to sex outside of a relationship (hook-ups)


A third gain in cognitive ability involves thinking about thinking itself, a process referred to as metacognition. It often involves monitoring one's own cognitive activity during the thinking process. Adolescents' improvements in knowledge of their own thinking patterns lead to better self-control and more effective studying. It is also relevant in social cognition, resulting in increased introspection, self-consciousness, and intellectualization (in the sense of thought about one's own thoughts, rather than the Freudian definition as a defense mechanism). Adolescents are much better able than children to understand that people do not have complete control over their mental activity. Being able to introspect may lead to two forms of adolescent egocentrism, which results in two distinct problems in thinking: the imaginary audience and the personal fable. These likely peak at age fifteen, along with self-consciousness in general.


A questionnaire called the teen timetable has been used to measure the age at which individuals believe adolescents should be able to engage in behaviors associated with autonomy. This questionnaire has been used to gauge differences in cultural perceptions of adolescent autonomy, finding, for instance, that White parents and adolescents tend to expect autonomy earlier than those of Asian descent. It is, therefore, clear that cultural differences exist in perceptions of adolescent autonomy, and such differences have implications for the lifestyles and development of adolescents. In sub-Saharan African youth, the notions of individuality and freedom may not be useful in understanding adolescent development. Rather, African notions of childhood and adolescent development are relational and interdependent.


Given the potential consequences, engaging in sexual behavior is somewhat risky, particularly for adolescents. Having unprotected sex, using poor birth control methods (e.g. withdrawal), having multiple sexual partners, and poor communication are some aspects of sexual behavior that increase individual and/or social risk. Some qualities of adolescents' lives that are often correlated with risky sexual behavior include higher rates of experienced abuse, lower rates of parental support and monitoring. Adolescence is also commonly a time of questioning sexuality and gender. This may involve intimate experimentation with people identifying as the same gender as well as with people of differing genders. Such exploratory sexual behavior can be seen as similar to other aspects of identity, including the exploration of vocational, social, and leisure identity, all of which involve some risk.


Research seems to favor the hypothesis that adolescents and adults think about risk in similar ways, but hold different values and thus come to different conclusions. Some have argued that there may be evolutionary benefits to an increased propensity for risk-taking in adolescence. For example, without a willingness to take risks, teenagers would not have the motivation or confidence necessary to leave their family of origin. In addition, from a population perspective, there is an advantage to having a group of individuals willing to take more risks and try new methods, counterbalancing the more conservative elements more typical of the received knowledge held by older adults. Risktaking may also have reproductive advantages: adolescents have a newfound priority in sexual attraction and dating, and risk-taking is required to impress potential mates. Research also indicates that baseline sensation seeking may affect risk-taking behavior throughout the lifespan.