Battle in 657 between two Muslim armies, the Iraqi forces of Caliph Ali ibn Abi Talib and the Syrian forces of the governor, Muawiyah. The two were reluctant to fight each other initially but engaged in battle after a seventy-seven-day stalemate. The battle ended in extensive bloodshed on both sides followed by an arbitration agreement. The Kharijis split from Ali due to the lack of a decisive victory. A major step toward the establishment of the Umayyad caliphate.