section_path: History by region/West and Central Asia
section_name: West and Central Asia
paragraph_text: West and Central Asia
  
  The Arabian Peninsula and the surrounding Middle East and Near East regions saw dramatic change during the post-classical era caused primarily by the spread of Islam and the establishment of the Arab caliphates.
  
  In the 5th century, the Middle East was separated by empires and their spheres of influence; the two most prominent were the Persian Sasanian Empire, centered in what is now Iran, and the Byzantine Empire in Anatolia (modern-day Turkey). The Byzantines and Sasanians fought with each other continually, a reflection of the rivalry between the Roman Empire and the Persian Empire seen during the previous five hundred years. The fighting weakened both states, leaving the stage open to a new power. Meanwhile, the nomadic Bedouin tribes who dominated the Arabian desert saw a period of tribal warfare for scarce resources and a familiarity with Abrahamic religions or monotheism.
  
  While the Byzantine and Sasanian Empires were both weakened by the Byzantine–Sasanian War of 602–628, a new power in the form of Islam grew in the Middle East under Muhammad in Medina. In a series of rapid Muslim conquests, the Rashidun army, led by the caliphs and skilled military commanders such as Khalid ibn al-Walid, swept through most of the Middle East, taking more than half of Byzantine territory in the Arab–Byzantine wars and completely engulfing Persia in the Muslim conquest of Persia. It would be the Arab caliphates of the Middle Ages that would first unify the entire Middle East as a distinct region and create the dominant ethnic identity that persists today. These caliphates included the Rashidun, Umayyad, and Abbasid Caliphates, along with the later Turkic-based Seljuk Empire.
  
  After Muhammad introduced Islam, it jump-started Middle Eastern culture into an Islamic Golden Age, inspiring achievements in architecture, the revival of old advances in science and technology, and the formation of a distinct way of life. Muslims saved and spread Greek advances in medicine, algebra, geometry, astronomy, anatomy, and ethics that would later find their way back to Western Europe.
  
  The dominance of the Arabs came to a sudden end in the mid-11th century with the arrival of the Seljuk Turks, migrating south from the Turkic homelands in Central Asia. They conquered Persia, Iraq (capturing Baghdad in 1055), Syria, Palestine, and the Hejaz. This was followed by a series of Christian Western Europe invasions. The fragmentation of the Middle East allowed joint European forces mainly from England, France, and the emerging Holy Roman Empire, to enter the region. In 1099 the knights of the First Crusade captured Jerusalem and founded the Kingdom of Jerusalem, which survived until 1187, when Saladin retook the city. Smaller crusader fiefdoms survived until 1291. In the early 13th century, a new wave of invaders, the armies of the Mongol Empire, swept through the region, sacking Baghdad in the siege of Baghdad and advancing as far south as the border of Egypt in what became known as the Mongol conquests. The Mongols eventually retreated in 1335, but the chaos that ensued throughout the empire deposed the Seljuk Turks. In 1401, the region was further plagued by the Turko-Mongol, Timur, and his ferocious raids. By then, another group of Turks had arisen as well, the Ottomans.