The death of Yazid in 683 led to a major leadership crisis in the caliphate, and "the power of his house seemed to collapse everywhere", in the words of Orientalist Julius Wellhausen [REF].
When Ubayd Allah arrived in Syria, he found it in political disarray; Caliph Mu'awiya II had died weeks into his rule and a power vacuum ensued with many Syrian noblemen, particularly from the Qaysi tribes, switching allegiance to the rival, Mecca-based caliphate of Abd Allah ibn al-Zubayr [REF].