The sect known as "the Assassins," a corruption of an Arabic word that means hashish smoker, is familiar to the West as a mystical cult of killers led by the "Man in the Mountain" encountered by the Crusaders. But it was not defeat at the hands of Christians that ended more than a century of Assassin rule; it was the massive and brutal invasion of Mongols from the East who conquered Assassin strong points and mountain fortifications one by one, crushing nearly all traces of this once fearsome sect. For nearly two centuries the Fâtimids, Shi'ite Muslims who believed Mohammed's daughter Fâtimah was his successor, attempted to control the Islamic world from their seat in Cairo.