Hassan-i Sabbah
He was born in Acre, the son of Badr al-Jamali, an Armenian mamluk who became Muslim. Badr was vizier for the Fatimids in Cairo from 1074 until his death in 1094, when al-Afdal succeeded him. Caliph Al-Mustansir Billah died soon afterwards, and al-Afdal appointed as caliph al-Musta'li, a child, instead of al-Mustali's much older brother Nizar ibn al-Mustansir. Nizar revolted and was defeated in 1095; his supporters, led by Hassan-i Sabbah, fled east, where Sabbah established the Nizari Isma'ili sect, known also as the order of Assassins.