Ali (Ali ben Abu Taleb), a Mohammedan caliph, reigned G55-661. He was adopted and brought up by Mohammed, his blood relation, married the prophet's daughter Fatima, and is believed to have been his first disciple. On the death of Mohammed without male issue, he bad claims as next of kin to the succession; but the deferred to those of Abubekr, Omar, and Oth-man, who were successively elected by the Moslems, and were supported by Ayesha, the prophet's widow, an inveterate enemy of Ali. It was not till after the assassination of Oth-man that he assumed the sovereign power. The question of his right to the succession divides the Mohammedan world into the two great sects of Sunnis and Shiahs, the former denying Ali's right, the latter affirming it. Ali's first act of power was the suppression of a rebellion fomented by other pretenders to the crown, who were abetted by Ayesha. The rebels Zobair and Talha were defeated and slain, and Ayesha was taken prisoner. A new opponent soon arose in Moawiyah, who succeeded in establishing himself in Damascus, and even carried the war into Ali's own territories and seized the two holy cities.

Three fanatics, having determined on ridding the world of both pretenders, succeeded in killing Ali, but failed in their attempt on the life of Moawiyah. Ali left three sons, one of whom, Hassan, succeeded him for a short time.