Fatimid control. In Tripolitania, the Hawwara Berbers were subdued as part of the consolidation of Fatimid rule over Tripoli, and their western neighbours, the Berbers of the Nafusa Mountains, were conquered in a series of campaigns in 922–923 by the Sulayman ibn Kafi al-Ijjani. An exception was Tahert, which served as a westerly outpost of Fatimid Ifriqiya, located some from the eastern edge of Ifriqiya proper. Its Fatimid governor, Masala ibn Habus, was a Miknasa Berber, which brought his tribe under the Fatimid banner. The efforts of the Miknasa to spread Isma'ilism in Ouarsenis, on the other hand, failed miserably, as the missionaries were simply killed by the local population. Likewise, in 922, the Kutama commander Fahlun and his men, trying to impose Fatimid rule in the Aurès, including heavy taxation and the dispatch of hostages to Mahdiya, were overwhelmed by the locals and killed in their sleep. Masala faced the Zenata under their leader Ibn Khazar, who repeatedly tried to wrest control of Tahert from the Fatimids. Masala was killed by his rival in November 924, and was succeeded by his brother, Yasal. Although the latter was able to repel a Zenata attack on Tahert in 925, the defeat of a Fatimid relief army by Ibn Khazar encouraged other Berber tribes in the area to rise in revolt. This forced al-Mahdi to sent al-Qa'im to deal with the revolt in person. The heir-apparent set out in April 917, issuing a call to arms not only for the Kutama tribes, but also the Arab and the subdued Berber tribes such as the Hawwara and Ajisa; to ensure the latter's loyalty, the sons of their chiefs were sent as hostages to Mahdiya. Al-Mahdi's old slave Su'luk, now known as the chamberlain Ja'far ibn Ubayd, subdued the Kiyana tribe in the Hodna Mountains, whereupon al-Qa'im established a new city, named al-Muhammadiya (modern M'Sila) after himself, to cement Fatimid control over the area. One of the earliest Isma'ili partisans, Ali ibn Hamdun al-Andalusi, was made its first governor. Ziri ibn Manad, the leader of another Berber tribe, the Sanhaja, also offered his submission to al-Qa'im at this time. Al-Qa'im then entered the Zenata lands in the Zab Mountains, denying them food and pasture, and launching a pursuit of Ibn Khazar. Conditions were hard: uninterrupted rainfall for over a month cut off communications with Mahdiya, where the court feared that the entire expedition was