Alamut is a mountain fortress at an altitude of 2163 meters at the central Alborz, in the Iranian stanza of Qazvin, about 100 kilometers from Tehran. In 1090 AD, the Alamut Castle, a mountain fortress in present-day Iran, came into the possession of Hassan-i Sabbah, a champion of the Nizari Ismaili cause. Until 1256, Alamut functioned as the headquarters of the Nizari Ismaili state, which included a series of strategic strongholds scattered throughout Persia and Syria, with each stronghold being surrounded by swathes of hostile territory.

Isma'ilism is a branch or sect of Shia Islam. The Isma'ili get their name from their acceptance of Imam Isma'il ibn Jafar as the appointed spiritual successor (imām) to Ja'far al-Sadiq, wherein they differ from the Twelver Shia, who accept Musa al-Kadhim, the younger brother of Isma'il, as the true Imām.