Al-Mansur Billah

Al-Mansur Billah, born Abu Tahir Isma'il in January nine hundred fourteen, ascended to the position of the thirteenth Isma'ili imam and the third caliph of the Fatimid Caliphate in Ifriqiya in nine hundred forty-six. His rise to power followed the death of his father, al-Qa'im, and was marked by a likely bloodless palace coup. At the time of his accession, the Fatimid realm was embroiled in turmoil, having lost significant territories to a large-scale revolt led by the Kharijite preacher Abu Yazid, who was besieging al-Qa'im's fortified coastal city of al-Mahdiya.

Unlike his father, Al-Mansur was an active and visible monarch, though his reign was marred by illness that ultimately led to his early demise. He took immediate action against the revolt, keeping his father's death a secret until the rebellion was suppressed. Acting as the designated successor and