Following the caliph’s victory over the Meccan faction at Basra, Ali bin Abi Talib turned his attention towards Syria. The Umayyad Mu’awiya bin Abu Sufyan had governed its lands for nearly two decades and insisted that he would not submit until his kin’s murderers and their unnamed instigators had been punished. This irresolvable dispute culminated to the battle of Siffin, the umma’s bloodiest civil war.