There has been great difficulty finding out much information about the origins of the Assassins because most early sources are written by enemies of the order, are based on legends, or both.
Most sources dealing with the order's inner workings were destroyed with the capture of Alamut, the Assassins' headquarters, by the Mongols in 1256.
However, it is possible to trace the beginnings of the cult back to its first Grandmaster, Hassan-i Sabbah (1050s–1124).
A passionate devotee of Isma'ili beliefs, Hassan-i Sabbah was well-liked throughout Cairo, Syria and most of the Middle East by other Isma'ili, which led to a number of people becoming his followers.
He had established a secret society of deadly assassins, which was built on a hierarchical structure.
Below Sabbah, the Grand Headmaster of the Order, were those known as "Greater Propagandists", followed by the normal "Propagandists", the Rafiqs ("Companions"), and the Lasiqs ("Adherents").
The Nizari were feared by the Crusaders, who referred to them collectively as "Assassins".