The Old Man of the Mountain (Latin : Vetulus de Montanis), [1] is the expression first used by Marco Polo in a passage from Book of the Marvels of the World , to indicate Hasan-i Sabbah, the grand master of the "Order of Assassins" (the Nizari Ismaili state) who was based in the mountain fortress of Alamut. It later became a common name used by the Crusaders. [2]
Subsequently, this nickname was given to various Isma'ili successors of Hassan, in Syria, particularly, [3] for example Rashid al-Din Sinan, the da'i (missionary) [4] and a leader of the Syrian branch of the Nizari Isma'ili state. [5]