Ali (c. 598–661)

Fourth caliph of Islam. He was born in Mecca, the son of Abu Talib, and was the cousin and close friend and supporter of the prophet Muhammad, who gave him his daughter Fatima in marriage. He was one of the first to believe in Islam. On Muhammad's death in 632, Ali had a claim to succeed him, but this was not conceded until 656, following the murder of the third caliph, Uthman. After a brief and stormy reign, Ali was assassinated. Controversy has raged around Ali's name between the Sunni Muslims and the Shiites, the former denying his right to the caliphate and the latter supporting it.

Ali's appointment as caliph led to opposition from Syria and parts of Arabia. After an inconclusive victory at Siffin, he agreed to submit the matter to arbitration, thus losing the moral victory. His son Hasan gave up his claim to the caliphate in favour of Muawiyah, governor of Syria. Ali's death marked the transfer of the centre of power of the Arab empire from Arabia, which henceforth became a backwater, to Syria.