The century following Muhammad’s death was dominated by military conquest and expansion. Muhammad was succeeded by the four “rightly-guided” Caliphs (khalifa or successor in Arabic): Abu Bakr (632-34 C.E.), Umar (634-44 C.E.), Uthman (644-56 C.E.), and Ali (656-661 C.E.). The Qur'an is believed to have been codified during Uthman’s reign. The final caliph, Ali, was married to Fatima, Muhammad’s daughter and was murdered in 661. The death of Ali is a very important event; his followers, who believed that he should have succeeded Muhammad directly, became known as the Shi’a ("party" or "followers"), referring to the followers of Ali. Today, the Shi’ite community is composed of several different branches, and there are large Shia populations in Iran, Iraq, and Bahrain. The Sunnis, who do not hold that Ali should have directly succeeded Muhammad, compose the largest branch of Islam; their adherents can be found across North Africa, the Middle East, as well as in Asia and Europe.
During the seventh and early eighth centuries, the Arab armies conquered large swaths of territory in the Middle East, North Africa, the Iberian Peninsula, and Central Asia, despite on-going civil wars in Arabia and the Middle East. Eventually, the Umayyad Dynasty emerged as the rulers, with Abd al-Malik completing the Dome of the Rock, one of the earliest surviving Islamic monuments, in 691/2 C.E. The Umayyads reigned until 749/50 C.E., when they were overthrown. The Abbasid Dynasty assumed the Caliphate and ruled large sections of the Islamic world. However, with the Abbasid Revolution, no one ruler would ever again control all of the Islamic lands.