section_path: Abstract
section_name: Abstract
paragraph_text: Iran, officially the Islamic Republic of Iran (IRI), also known as Persia, is a country in West Asia. It borders Turkey to the northwest and Iraq to the west, Azerbaijan, Armenia, the Caspian Sea, and Turkmenistan to the north, Afghanistan to the east, Pakistan to the southeast, the Gulf of Oman and the Persian Gulf to the south. With a mostly Persian-ethnic population of almost 90 million in an area of 1,648,195 km (636,372 sq mi), Iran ranks 17th globally in both geographic size and population. It is the sixth-largest country entirely in Asia and one of the world's most mountainous countries. Officially an Islamic republic, Iran has a Muslim-majority population. The country is divided into five regions with 31 provinces. Tehran is the nation's capital, largest city and financial center.
  
  A cradle of civilization, Iran has been inhabited since the Lower Palaeolithic. It was first unified as a state by Deioces in the seventh century BC, and reached its territorial height in the sixth century BC, when Cyrus the Great founded the Achaemenid Empire, one of the largest in ancient history. Alexander the Great conquered the empire in the fourth century BC. An Iranian rebellion established the Parthian Empire in the third century BC and liberated the country, which was succeeded by the Sasanian Empire in the third century AD. Ancient Iran saw some of the earliest developments of writing, agriculture, urbanisation, religion and central government. Muslims conquered the region in the seventh century AD, leading to Iran's Islamization. The blossoming literature, philosophy, mathematics, medicine, astronomy and art became major elements for Iranian civilization during the Islamic Golden Age. A series of Iranian Muslim dynasties ended Arab rule, revived the Persian language and ruled the country until the Seljuk and Mongol conquests of the 11th to 14th centuries.
  
  In the 16th century, the native Safavids re-established a unified Iranian state with Twelver Shi'ism as the official religion. During the Afsharid Empire in the 18th century, Iran was a leading world power, though by the 19th century, it had lost significant territory through conflicts with the Russian Empire. The early 20th century saw the Persian Constitutional Revolution and the establishment of the Pahlavi dynasty. Attempts by Mohammad Mosaddegh to nationalize the oil industry led to an Anglo-American coup in 1953. After the Iranian Revolution, the monarchy was overthrown in 1979 and the Islamic Republic of Iran was established by Ruhollah Khomeini, who became the country's first Supreme Leader. In 1980, Iraq invaded Iran, sparking the eight-year-long Iran–Iraq War, which ended in stalemate.
  
  Iran is officially governed as a unitary Islamic Republic with a Presidential system, with ultimate authority vested in a Supreme Leader. The government is authoritarian and has attracted widespread criticism for its significant violations of human rights and civil liberties. Iran is a major regional power, due to its large reserves of fossil fuels, including the world's second largest natural gas supply, third largest proven oil reserves, its geopolitically significant location, military capabilities, cultural hegemony, regional influence, and role as the world's focal point of Shia Islam. The Iranian economy is the world's 19th-largest by PPP. Iran is an active and founding member of the United Nations, OIC, OPEC, ECO, NAM, SCO and BRICS. Iran is home to 28 UNESCO World Heritage Sites, the 10th highest in the world, and ranks 5th in Intangible Cultural Heritage, or human treasures.