In 448 the Turk, Tughril Beg, was recognised in Baghdad as the Sultan and lieutenant of the Khalif. The Saljuq Turks were strictly orthodox, and indeed at this time recognised themselves as the champions of orthodoxy. When, two years later, the general of the troops in Baghdad, a Turk named Arslan al-Basasiri, revolted against the Khalif al-Kaʾim and expelled him from Baghdad, he put the seal on his revolt by causing the _khutba_ to be said throughout Mesopotamia in the name of the Fatimid al-Mustansir, and sent him his protestation of allegiance. The expelled ʿAbbasir Khalif took refuge with the Emir of the Arabs and stayed with him one year, and then the Saljuq Tughril Beg came to his relief, and having attacked and slain al-Basasiri, reinstated the ʿAbbasid in Baghdad. The Khalif made his entry into the city exactly one year after his expulsion, so that Fatimid al-Mustansir had just one year’s nominal recognition in Mesopotamia, but this cannot be seriously regarded as an extension of the Fatimid dominion.
The proclamation of the Fatimid Khalifate in Baghdad and the exile of the ʿAbbasid Khalif from his capital raised unduly high expectations in Egypt. The more so as the official robe and jewelled turban of the Baghdad Khalif, as well as the iron lectern, were carried off to Cairo, and remained there until the fall of the Fatimids. Al-Mustansir was confident that these symbols would be soon followed by the ʿAbbasid in person, and laid out a large sum, stated to be no less than two million dinars, in preparing the second palace which stood facing his own dwelling across the great square in Kahira for the occupation, as he hoped, of his illustrious captive.
In fact, however, the Fatimid Khalifate had already passed its happiest hours and was rapidly approaching its decline. The Arabs still held Tripoli and Barqa as subjects of Egypt, but this was the western limit of Fatimid rule and the death of Anushtakin had practically ended its authority in Syria.
Just about this time, however, there was a temporary restoration of Fatimid authority in the Hijaz, and this not due to a rebel like al-Basasiri, but to the work of a devout and earnest Shiʿite. Abu l-Hasan ʿAli b. Muhammad b. ʿAli as-Sulaihi was the son of a Qadi of Yemen, a strict and orthodox Sunni. The son, however, came under the influence of an Ismaʿilian missionary named ʿAmir b. ʿAbdullah az-Zawwahi who, concealing his Shiʿite opinions, was received into great favour by the Qadi, but in private intercourse with the son taught him the Fatimid system of canon law and the _tawil_ or allegorical interpretation of the Qurʾan. For fifteen years as-Sulaihi acted as guide to the Meccan pilgrims along the road between as-Sarat and Taif, then in 429 he broke out in revolt against the established government and, at the head of sixty followers, whom he bound by oath, seized upon Mount Mashar. Secretly he supported the Khalifate of Mustansir, but this he concealed for fear of Najah, the Chieftain of the Tihama. In 452 he presented Najah with a beautiful female slave who, acting under his directions, poisoned Najah and then released from all need of concealment openly proclaimed the Fatimid Imamate. Three years later we find him the master of all Yemen, having his headquarters at Sanaʿa, and for nearly twenty years the _khutba_ in the cities of Yemen, and for part of that time also in the holy cities of the Hijaz made mention of the name of the Khalif al-Mustansir.