After Uthman's death, Ali, a cousin and son-in-law of Muhammad, became caliph and moved the capital from Medina to Kufa, where Mukhtar held some minor office under him, and Mukhtar's uncle became governor of nearby al-Mada'in. A few companions of Muhammad, including Mu'awiya, the governor of Syria, refused to recognise Ali's authority, and war broke out. The Battle of Siffin ended in stalemate (July 657), when Ali's forces refused to fight in response to Mu'awiya's calls for arbitration. Ali reluctantly agreed to talks but a faction of his forces, later called Kharijites, broke away in protest, condemning Ali's acceptance of arbitration as blasphemous. Arbitration could not settle the dispute between Mu'awiya and Ali and the latter was subsequently murdered by a Kharijite in January 661.