Hassan I Sabbah was a Persian missionary, scholar, and leader of the Nizari Ismailis, best known for founding the Order of Assassins in the late 11th century. Operating from the
mountain fortress of Alamut in present-day Iran, he established a powerful network of devoted followers through rigorous religious indoctrination and military strategy. His rule was marked by an emphasis on discipline, secrecy, and the strategic use of targeted assassinations to counter more powerful enemies, including Seljuk rulers. Though his
methods were feared, he was also a patron of knowledge, fostering an intellectual environment at Alamut that preserved and advanced various sciences. Hassan’s legacy
endures as a figure of both legend and controversy.