Member of Muhammad's Household, first of the Shia Imams, and fourth Sunni Caliph (601-661)

Ali ibn Abi Talib was a cousin, son-in-law and companion of the Islamic prophet Muhammad, who ruled as the fourth caliph from 656 until his assassination in 661. He is one of the central figures in Shia Islam and is regarded as the rightful immediate successor to Muhammad as an Imam by Shia Muslims.