Al-Mansur Billah, caliph of the Fatimid Caliphate (b. 913)
Abu Tahir Isma'il (Arabic: أبو طاهر إسماعيل, romanized: Abū Ṭāhir ʾIsmāʿīl; January 914 – 18 March 953), better known by his regnal name al-Mansur bi-Nasr Allah (Arabic: المنصور بنصر الله, romanized: al-Manṣūr bi-Naṣr Allāh, lit. 'The Victor with the Help of God'), was the third caliph of the Fatimid Caliphate in Ifriqiya, ruling from 946 until his death. He presided over a period of crisis, having to confront the large-scale Kharijite rebellion of Abu Yazid. He succeeded in suppressing the revolt and restoring the stability of the Fatimid regime.