Alamut, Castle of the Assassins, northeast of Ghazvin, Zanjun Province. The Frankish knights who returned to Europe from the Crusades during the eleventh and twelfth centuries took with them tales of 'The Old Man of the Mountain', the leader of a religious sect known as the Assassins, who lived ina series of mountain fortresses near the source of the Alamut river, deep in the Alborz mountains of northern Iran. The most famous of the castles was Alamut, built around 860 on a rocky outcrop above the village of Gazur Khan, about 80km northeast of Ghazvin. The name of the sect may derive fromt he hashishiyun (hashish), the taking of which is said to have enabled the sects members to carry out the political murders of prominent Muslim figures. The Assassins were an offshoot of the Sevener Shi'ites (followers of the Seventh Imam, Ismail) and were considered a threat by the Sunnis. The group considered themselves to be the guardians of their faith and conducted a campaign of terror for 120 years. In 1092 they murdered Nizam al-Mulk, the prime minister of the Seljuk Turks, a Sunni and a Persian.