Muzaffar was initially appointed to head the security (shurtah) of Egypt by his father Kaydar Nasr ibn 'Abdallah, after the latter was made governor of the province in 832. Following the death of Kaydar in the spring of 834, however, Muzaffar assumed the governorship himself. He immediately moved to put down a revolt, led by Yahya ibn al-Wazir al-Jarawi, which had broken out during his father's lifetime, and defeated the rebels in a battle near Tinnis.