The word “assassin” comes from hashshashin, meaning hemp-eaters, a name given to a secretive band of Muslims in Persia and Asia Minor in the 11th through the 13th centuries.
The shadowy group, officially called the Nizari Isma’ilites, supposedly smoked hashish and killed their enemies while under its influence.
Led by Hasan-e Sabbah, who believed that terrorism was a sacred religious duty, the Nizari Isma’ilites created a secret network of propagandists, double agents, spies, and killers.
Sabbah placed agents in enemy camps who then would patiently work their way into positions of trust, until the signal came to kill and slip into the night. They claimed many victims among generals and statesmen, including two caliphs.
Although their murders and treachery have been well documented, historians believe that the story about getting high before assassinations may have been a myth of the time.
It kinda makes sense, hashish seems like the entirely wrong drug for a job that requires trickery, quick-wittedness, and fast footwork.