along with the expelled members of the Buyid clan, but Sabuktakin forced him back and confined him to his palace. Al-Muti' was induced to abdicate with his health as a pretext, and was replaced by his oldest son, Abu Bakr Abd al-Karim, as Caliph al-Ta'i' li'llah on 5 August 974 (13 Dhu'l-Qa'dah 363 AH). This was the first father-to-son succession of the caliphate since al-Muktafi in 902. Like his father, al-Ta'i' is considered by medieval and modern historians alike to have been a powerless figurehead, limited to appending his name to certificates of appointment and official correspondence, with others holding the real power. He played no role even in the numerous religious controversies of his day, and little is known about his activities other than his often conducting the Friday prayer at the Kadhimayn mosque, and his rebuilding the , one of the principal gates to the caliphal palace complex. The historian Heribert Busse however points out that al-Ta'i' managed to maintain his office for sixteen years in a very turbulent time, involving no fewer than six regime changes in Baghdad, and credits him with political acumen and flexibility. The new caliph promptly named Sabuktakin as the chief emir (), with the honorific title . Before long, Sabuktakin, accompanied by al-Ta'i' and al-Muti', marched on Wasit, where the Buyid forces under Izz al-Dawla and his cousin, Adud al-Dawla, the ruler of Fars, gathered. Sabuktakin died on the way, and was succeeded by another Turkic , Alptakin. The Turks were defeated in January 975 near the Diyala River, and withdrew north to Tikrit, before they fled to Syria, while the Buyids entered Baghdad. Al-Ta'i's position under the Turks is unclear. He sent letters to Izz al-Dawla berating him of his errors and omissions as governor, but in later public letters he cursed them and claimed that he had been using dissimulation () in apparently siding with them. Thus historian John Donohue writes of the "brief six months of independence that the caliphate enjoyed under the Turk rebels", while Heribert Busse writes of the caliph as being virtually the prisoner of the Turks. At any rate, al-Ta'i' was soon able to recover his position at least somewhat, making use of the Buyids' quarrels and their need for legitimacy: in Baghdad, Adud al-Dawla deposed his cousin and assumed rule of the city. Leaving Tikrit, al-Ta'i' returned to Baghdad, where Adud al-Dawla received him