 The deaths of Yazid and his son and successor Mu'awiya II in relatively quick succession in 683–684 precipitated a leadership vacuum in Damascus and the consequent collapse of Umayyad authority across the Caliphate.Most provinces declared their allegiance to the rival Mecca-based caliph Abd Allah ibn al-Zubayr.In parts of Syria, older-established Arab tribes who had secured a privileged position in the Umayyad court and military, in particular the Banu Kalb, scrambled to preserve Umayyad rule.