THE THIRD FATIMID KHALIF, AL-MANSUR (A.H. 335-342 = A.D. 946-953) The stability of the Fatimid Khalifate was problematical when al-Qaʾim died at the height of Abu Yazid’s rebellion. The first task of the new Khalif al-Mansur was to relieve Susa, and he was fortunate enough to inflict a severe defeat on Abu Yazid, and to drive him back to the mountains of Kiana in the extreme west of Ifrikiya. There a stubborn struggle followed which lasted a whole year, but was terminated by the final defeat and complete rout of the insurgent Berbers, Abu Yazid himself being mortally wounded in the final engagement and dying soon after. This revolt, however, begins the decay of Fatimid authority in the west. The Zanata tribes of Maghrawa and B. Ifrene were able to form a separate state in the neighbourhood of Tlemsen, whilst the Umayyads of Spain established a colony at Fez, where they placed the descendants of Musa ibn Abi l-Afia and his followers, Syrian Arabs who had been invited to Spain but had become obnoxious, and whom it was advisable to segregate from the earlier settlers in Spain. Central Maghrab, roughly corresponding to the greater part of Algeria, was held by the Sanhaja tribe, steady allies and supporters of the Fatimid Khalifate, under the government of Ziri b. Menad, who built the town of Achir as his capital. Such was the position when al-Mansur died in 342 and was succeeded by his son Maʿad, who took the name of al-Moʿizz. Al-Mansur’s reign had been occupied entirely in dealing with Abu Yazid’s rebellion, and in the consolidation of the country after this rebellion had been put down. It cannot be said that he left the Fatimid state in a strengthened position when compared with conditions under the Mahdi, for already independent states had begun to be formed in the West, but he had dealt successfully with the emergency existing at the time of his accession.