The English word assassin descends from hashshashin, a term Crusader era Europeans in the Levant applied to the Nizari Ismailis, and medieval European writers built an elaborate legend around it. Marco Polo's account, the most famous version, describes an Old Man of the Mountain who kept young men drugged in a hidden garden of earthly delights, convinced them they had glimpsed paradise, then dispatched them on suicidal killing missions with the promise that death in his service would return them to that garden permanently. For centuries this story stood as the standard European explanation for the order's fida'i and for the word assassin itself.
Modern scholarship treats the garden and drug story as a hostile legend rather than documented history. Farhad Daftary's study of the assassin legends traces how Crusader misinformation, religious hostility toward the Nizaris as a Shia Ismaili sect, and simple unfamiliarity with the Ismaili world combined to produce a narrative with little basis in the order's own surviving sources, which describe a disciplined and doctrinally serious movement rather than a cult of intoxicated killers. Bernard Lewis's scholarship reaches a similar conclusion from Persian and Arabic sources, treating the hashshashin label as most likely a term of reproach rather than a literal report of drug use.
What survived the legend is the Nizari Ismaili faith the order defended, which continues today as a living branch of Shia Islam under a hereditary imamate, currently held by the Aga Khan, whose community traces its religious lineage directly back to the imams the Alamut state was built to protect, a continuity the sensational assassin legend has always obscured rather than illuminated.