Order of Assassins
The Nizari Ismaili sect that used targeted killing from mountain fortresses across the medieval Middle East, giving the world the word assassin.
The Order of Assassins was a network of mountain fortresses run by the Nizari Ismailis, a branch of Shia Islam, from 1090 to 1256. Its founder, Hasan-i Sabbah, turned a small and persecuted religious community into something feared by the most powerful rulers in the Middle East. The Nizaris had no field army and held only scattered valleys and mountaintops. Instead of fighting battles, they killed the men who ordered battles: viziers, emirs, and kings. The killers struck in public and usually made no attempt to escape. The word "assassin" in English and many other European languages comes from the name their enemies gave them.
How Hasan-i Sabbah built the Order of Assassins
Hasan-i Sabbah was born in the 1050s in Qom, in what is now Iran, to a Twelver Shia family. Around the age of seventeen he converted to Ismaili Shia Islam. He traveled to Fatimid Egypt for religious training in the late 1070s, and when he returned to Persia he began preaching and recruiting followers across the Seljuk empire.
In September 1090, Hasan took the castle of Alamut, high in the Alborz mountains of northern Iran. He did it without a battle. Over months he had sent preachers into the surrounding villages and converted soldiers in the garrison one by one. The castle's commander left peacefully and was later paid 3,000 gold dinars in compensation. Alamut sat on a narrow rock ridge above a valley, nearly impossible to attack from below, and Hasan made it the center of a new state.
Over the following years, his followers took a chain of similarly remote fortresses in Persia and eventually in Syria. In 1094, the Ismailis broke with the Fatimid caliphate in Cairo after a fight over who would succeed the caliph, backing a claimant named Nizar. That made them isolated on every side. The Sunni Seljuk empire surrounded their scattered strongholds and considered them heretics to be destroyed.
Hasan governed from Alamut for 34 years and, according to Persian historians, never once came down from the castle. He spent his time reading, writing, and running his network of fortresses. He imposed strict rules on his community and on himself. When one of his sons was accused of murder, Hasan had him executed. When the other was suspected of drinking wine, Hasan had him executed too. He sent his wife and daughters to another castle, where they supported themselves by spinning. He died at Alamut in June 1124, around the age of 73.
How the Order of Assassins used targeted killing
The Nizaris were heavily outnumbered. The Seljuk state could raise forces numbering in the tens of thousands. Hasan chose to target the leaders who sent those forces rather than the forces themselves.
The killer was called a fida'i, a trained devotee who might spend months or even years in position, sometimes taking service in a target's household as a guard, secretary, or servant. He struck in crowded places, often at a mosque during Friday prayers, most often with a knife, and rarely tried to escape. The publicity of each killing was central to how it worked. A ruler could never be certain that the man standing behind him was not already a Nizari agent. No bodyguards could reliably stop a killer who expected to die.
The first major target was Nizam al-Mulk, vizier of the Seljuk empire and its most influential official, stabbed by a man disguised as a Sufi in 1092. Over the following decades, scores of military commanders, provincial governors, and religious leaders were killed.
In Syria, the Nizari branch was led by Rashid al-Din Sinan. European writers from the Crusader states gave him the title the Old Man of the Mountain. His agents killed Conrad of Montferrat, who had just been chosen as king of Jerusalem, in the streets of Tyre in April 1192. Saladin was targeted twice by the Nizaris, in 1175 and 1176. Both attempts failed. Saladin besieged the Nizari fortress of Masyaf in response, but withdrew after about a week and made terms with Sinan rather than pressing the campaign.
Where does the word "assassin" come from?
The word comes from "hashishiyya" or "hashishin," a term that other Muslims used for the Nizari Ismailis. Despite the link to the Arabic word for hashish, the name was almost certainly a slur meaning something like "rabble" or "outcasts," not a reference to drug use. No reliable evidence supports the idea that the Nizaris used hashish in their operations.
The drug story comes mainly from European travelers. Marco Polo, writing in the late 1200s, described a hidden garden at Alamut where young recruits were drugged, given a glimpse of paradise, and promised they would be sent back there if they carried out a killing. The tale spread widely in Europe, but scholars consider it a legend. The sources from within the Nizari community describe a disciplined, literate society with libraries and an active intellectual tradition.
The word entered European languages through the Crusaders. By the early 1300s, Italian writers were using "assassino" to mean simply "murderer."
What happened to the Order of Assassins?
In the 1250s, the Mongol armies of Hulagu Khan, a grandson of Genghis Khan, moved west through Persia. The Nizari fortresses fell one by one. Alamut surrendered in December 1256. Before the Mongols destroyed its famous library, Hulagu's court historian, Juvayni, was allowed to enter, save a few volumes, and copy passages from a biography of Hasan-i Sabbah. The rest, one of the largest collections of Ismaili theological writing, was lost. The fall of Baghdad followed a little over a year later.
The destruction of Alamut ended the Order as a political and military force, but not as a faith. The Nizari Ismailis still exist as a global community of roughly 12 to 15 million people in more than 35 countries. Their line of imams has continued unbroken since Alamut. In 2025, Prince Rahim al-Hussaini became the Aga Khan, the 50th hereditary imam, succeeding his father, who had led the community since 1957. The Nizari Ismailis are known today for their development work, hospitals, and universities.