When Harith arrived at Marw in early July 745, however, the situation had changed: Yazid was dead, a full-blown civil war had erupted in Syria, and Nasr ibn Sayyar, although still occupying the position of governor, lacked authority. Although he recognized Marwan II (), most of his own followers did not accept Marwan as Caliph. Harith was quick to distance himself from Nasr: he refused the offer of a district governorship, and distributed the gifts he received among his supporters. Harith vocally denounced Marwan II, and was soon joined by 3,000 of his fellow Tamimis, while his secretary, Jahm ibn Safwan, drummed up further support. Within a short time, he had become a graver threat to Nasr than al-Kirmani. After attempts to negotiate an agreement proved fruitless, Nasr attacked Harith's forces in March 746, and scored a first victory over them, in which Jahm ibn Safwan fell. At this point, al-Kirmani joined forces with Harith, and together they forced Nasr to abandon Marw and withdraw to Naysabur. The two allies entered the capital of Khurasan, but within days fell out and began fighting each other. In these clashes, Harith was killed, leaving al-Kirmani the master of the city. The conflict between Nasr and al-Kirmani continued, but was soon overtaken by events: exploiting the conditions of civil war, the Abbasids under Abu Muslim launched their own anti-Umayyad revolt in Khurasan. Nasr ibn Sayyar tried to conclude an alliance with al-Kirmani, but failed when the latter was murdered by one of Harith's sons in revenge. Abu Muslim managed to exploit the situation to his advantage, and in early 748, his men entered Marw, the first step in a war that would lead to the fall of the Umayyad dynasty and its replacement with the Abbasids two years later.