After the death of Uthman at the hands of protestors in 656, Ali claimed the Caliphate. He defeated one group of dissenters (led by Aisha and some of Muhammad's companions), but fought Mu'awiya to a standstill and submitted to arbitration. This angered those of his own supporters who rejected the concept of negotiation by the Caliph (these were the Kharijites), so he had to fight them as well.

Despite battlefield success against the Kharijites, Ali was assassinated by a Kharijite in 661. Mu'awiya induced Ali's son to abdicate and declared himself Caliph that same year, inaugurating the Umayyad Caliphate.