Assassins, a name originally applied by the Crusaders and other medieval Europeans to the Nizārī Ismailis of Syria. The Nizārī Ismailis were a minority Shiʿi Muslim community, who under the initial leadership of the dāʿī Ḥasan-i Ṣabbāḥ (d. 518/1124), in around 483/1090 founded a state in Persia. This state was centred at the stronghold of Alamūt (q.v.) in the Caspian region, with a subsidiary in Syria. The Persian part of this state was destroyed by the Mongols in 654/1256.

The Syrian Nizārīs had numerous military and diplomatic encounters with the Crusaders from the openi…