caliphate, but on the other, it recognized the Kutama as 'faithful' () or 'friends of God' (), an elite distinct from the mass of ordinary Muslims. The army remained at Sijilmasa for several weeks, during which delegations offering submission came from across the western Maghreb. The fugitive emir of Sijilmasa was captured, and the Kutama chieftain Ibrahim ibn Ghalib installed as governor. On 12 October, the army began its return march. It relieved Tahert, which in the meantime had come under attack by the Zenata under Ibn Khazar, attacked the tribe of Sadina in its mountain strongholds, and launched an expedition to capture Ibn Khazar, but the latter managed to flee into the desert. The army then turned northeast, and visited Ikjan, the original base of Abu Abdallah's mission among the Kutama. There Sa'id arranged the affairs of the Kutama tribes, and took care to gather the treasures that had for years been hoarded in his name. After twenty days, the army marched on towards Kairouan, wher on 4 January 910 the city notables came forth to greet their new ruler. Asked for a renewal of Abu Abdallah's , Sa'id immediately guaranteed their lives, but pointedly did not say anything about their possessions. The new caliph did not enter Kairouan—which he seems never to have visited during his life—and instead rode straight for Raqqada. On the next day, Friday, 5 January 910, in the sermon of the Friday prayer, a manifesto hailing the return of the caliphate to its rightful possessors, the Family of Muhammad, was read, and the name and titles of the new ruler were formally announced: "Abdallah Abu Muhammad, the Imam rightly guided by God, the Commander of the Faithful". Challenges of a revolutionary regime The proclamation of al-Mahdi as caliph was the culmination of the decades-long efforts of the Isma'ili , and the first time since the caliphate of Ali ibn Abi Talib (656–661) that a member of the Family of Muhammad governed a major part of the Muslim world. However, al-Mahdi and his successors were not only the secular rulers of a state (), but concurrently also Shi'a imams, at the head of the still extant and wide-ranging network of the , and thus posed a direct ideological challenge to the Sunni Abbasids for the leadership of the entire Islamic world. Already in his inaugural proclamation, al-Mahdi claimed a mandate to "conquer the world to