Battle of Siffin

The Battle of Siffin was the largest engagement of the First Fitna, fought between the forces of the Caliph Ali ibn Abi Talib and the Syrian governor Muawiyah ibn Abi Sufyan, who refused to give allegiance until Uthman's killers were brought to justice. The two armies faced each other for months on the banks of the Euphrates before serious fighting erupted. After prolonged battles in which thousands were killed on both sides, Muawiyah's forces attached pages of the Quran to their spears, calling for arbitration by the Book of Allah. Ali's army, particularly the Kharijite faction within it, insisted on accepting this call, although Ali himself was reportedly reluctant. The arbitration at Adhruh ended inconclusively and satisfied no one. The episode led to the emergence of the Kharijites who considered both Ali and Muawiyah to have erred, and Ali was later assassinated by a Kharijite. Ahl us-Sunnah regards all parties as sincere Muslims in error on a political question, and refrains from cursing any companion.