As a result, resentful Berbers grew receptive to radical Kharijite activists from the east (notably of Sufrite and later Ibadite persuasion) which had begun arriving in the Maghreb in the 720s. The Kharijites preached a puritan form of Islam, promising a new political order, where all Muslims would be equal, irrespective of ethnicity or tribal status, and Islamic law would be strictly adhered to. The appeal of the Kharijite message to Berber ears allowed their activists to gradually penetrate Berber regiments and population centers. Sporadic mutinies by Berber garrisons (e.g. under Munnus in Cerdanya, Spain, in 729-31) were put down with difficulty. One Ifriqiyan governor, Yazid ibn Abi Muslim, who openly resumed the "jizya" and humiliated his Berber guard by branding their hands, was assassinated in 721.