Today the word assassin is defined in the English dictionary as a murderer of prominent people, but that definition only began to appear after the tenth century. The word assassin originated from the Arabic word for hashish (hashishin). Before the word was given to murderers it was given to a small group of Muslims known as the Nizari Ismailis, who were a minority. Stories of martyrs carrying out public suicide assassinations by order of their leader the "old man of the mountains", as well as secret practices involving mind-altering drugs and secret garden paradises are some of the legends surrounding this group. Due to opposing Muslim groups as well as Crusading Europe the Nizari Ismailis were known as a sinister group of drugged assassins, only interested is murder and mischief. The stories surrounding the Nizari Ismailis are clearly fabricated because of the group's culture and priorities, therefore the legends are a product of the political agendas of opposing Muslim groups who introduced the myths and the European Crusaders who embellished the myths.
The culture, priorities and advancements of the group do not reflect those of a community of killers. Prior to being known as the Assassins the group reigned as the caliphs of the Fatimid Dynasty, its capital, Cairo became the de facto center of science, art, and philosophy. This achievement was of great importance to Shi"ism as a whole because this marked the first time since the time of Ali that a Shia imam was given political leadership of an entire Muslim state, also the Ismaili imams who were the Fatimid caliphs were treated as the official voice of Shi"ism. The Fatimids established a vast network of trade and commerce after settling down in Egypt. In direct rivalry with the Abbasids who used the Persian Gulf for trading purposes, the Fatimids successfully developed another trade route to India passing through the Red Sea.