Mu'awiya ultimately prevailed in the conflict and became caliph in 661. He restarted the campaigns against Byzantium after the lull caused by the civil war and in 665 appointed Sufyan alongside his own son Yazid to lead a summer raid against the Byzantines; Sufyan and his men entered Byzantine territory before Yazid, but shortly after withdrew as a result of disease. In the medieval Muslim accounts of al-Ya'qubi (d. ) and al-Tabari (d. 923), Sufyan was a commander of a raid against Byzantine territory in 670/71. According to the Muslim traditional historians al-Waqidi (d. 822), Khalifa ibn Khayyat (d. 854), al-Ya'qubi and al-Tabari, Sufyan led an expedition against the Byzantines in 672, during which al-Waqidi and al-Ya'qubi state he died. According to the Syriac historian Theophilus of Edessa (d. 785), Sufyan was slain with 30,000 of his men by a Byzantine army led by the patricians Florus, Petronas and Cyprian in 673/74; Michael the Syrian (d. 1199) further notes that the location of the battle was at a Lycian coastal city under siege by the Arabs. The battle was a turning point at this stage of the Arab–Byzantine wars, setting the Byzantines up for a counter-offensive over the following several years. In the biography of Sufyan by Ibn Asakir (d. 1176), Sufyan is said to have been killed in Byzantine territory in 674.