Even though assassins are a branch of Shiism, it is mainly known with Hasan Sabbah. Sabbah was bom in the Saljuqid state and was raised as a devout Shia. He went to Egypt to meet with Caliph Mustansir and got novel information from him. Then, he returned to the Saljuqid lands and initiated a new movement The main objective of this movement was to improve Shiism and to demonstrate that the Saljuqid state and the Sunni Caliph, resided in Baghdad, as illegitimate. Assassins interpreted Islamic principles according to their own purposes and explained these principles with heterodox explanations. In order to reach their targets, they utilized violence and terror as instruments and killed any individual that did not share their beliefs from different segment of society. Chaos and terror that were initiated by them caused many problems and suffering in the Islamic world