fedayee, a term used in Islamic cultures to describe a devotee of a religious or national group willing to engage in self-immolation to attain a group goal. The term first appeared in the 11th–13th centuries in reference to the members of the Nizārī Ismāʿīlī sect of Assassins who would risk their lives to commit political murder, an assignment considered a religious duty. Though fidāʾiyyūn (fedayeen) may have constituted a special body of “Assassins,” accounts of their taking hashish as a stimulant are not supported by evidence.
In the early 20th century fadāʾī designated a liberal thinker during the constitutional revolution in Iran. Beginning in the early 1940s, an Iranian militant group, Fadāʾiyyān-e Eslām, engaged in a series of political assassinations. From the 1950s on, fedayeen (fidāʾiyyūn) came to mean guerrilla fighters or commandos—referring at first to those operating in Egypt against British forces near the Suez Canal and later to Palestinians operating against Israel from bases in Syria, Lebanon, and Jordan in an effort to reestablish Arab hegemony in historic Palestine. In the mid-1990s the name was adopted by a militia organization attached to Iraq’s leader Ṣaddām Ḥussein; members of Fedayeen Ṣaddām (Fidāʾī Ṣaddām) engaged in guerrilla operations against U.S. and British forces during the Anglo-American invasion of Iraq in 2003.