shaykh al-jabal

The term "Shaykh al-Jabal" is an Arabic title meaning "mountain chief". This title was famously applied to the leader of the Nizari Ismailis, a religio-political movement within Islam that emerged in the 11th century. The Nizari Ismailis, often referred to by Crusaders as the "Assassins," established strongholds in mountainous regions, most notably the fortress of Alamut in Iran.123

The leader, Hasan-e Sabbah, and his successors commanded a network of fortresses and agents. The "mountain chief" title was a mistranslation by Crusaders of the Arabic term. The Nizari Ismailis were known for their covert operations, dispatching devotees to assassinate prominent figures. Their power waned after the Mongol invasions in the 13th century.231