Ḥasan ibn al-Ḥāfiẓ was a younger son of the eleventh Fatimid caliph and imam of Hafizi Isma'ilism, al-Hafiz, and vizier and heir-apparent of the Fatimid Caliphate from 19 July 1134 until his death in March 1135. Hasan came to power rebelling against his own father, and had allegedly espoused Sunnism. His reign was marked by brutality and repression which cost him support, and sparked another uprising that resulted in his downfall. He was poisoned by al-Hafiz, and succeeded by Bahram al-Armani.