Al-Hassan As-Sabbah, founder of the Assassins

Al-Hassan As-Sabbah is the founder of the first organized gang groups, relying on "hashish" drug dealing. His men were called "Hashasheen" in Arabic, i.e. people who dope "hashish" (a drug type), during the Umayyad Caliphate in Damascus, and hence, the word "Hashasheen" became gradually "Assassin" in English!