حسن الصباح
Founded by Hassan-i Sabbah, the Assassins were active in the fortress of Alamut in Persia from the 8th to the 14th centuries, and later expanded into a "de facto" state by acquiring or building many scattered strongholds. The group killed members of the Abbasid, Seljuk, Fatimid, and Christian Crusader elite for political and religious reasons.