The history of the word assassin, and the original Middle Eastern sect of political dissidents that went under the name the Assassins, has been thoroughly distorted by myth and propoganda over the many years since the group’s formation. Some of the tales seem wildly fantastical (because they are), and if you dig beneath the sand of time you’re likely to find the facts that gave birth to some of these wild speculations and fantastical rumors.
First of all, let’s start with the facts. The name Assassins comes from the idea that these men were “followers of Hassan,” named for al-Hassan ibn-al-Sabbah who was the head of the Ismailians. The Ismailians were a sect of extremists that gained power in the early 11th century. This group achieved a variety of smaller victories, such as the seizing of the Castle of Alamut. Hassan earned the nickname the “Old Man of the Mountain,” because this castle became the stronghold of the Assassins and it was where he ruled his fanatical operation with an iron fist.
The Assassins, as a political group, held several areas through a combination of brute force and terrorist tactics. According to some sources the followers of Hassan also were hired out as mercenaries on several occasions, which no doubt added to their loathesome reputation. However, being fundamentalist followers of Islam these warriors were not allowed to enjoy many things, including alcohol or other intoxicants (this by Hassan’s own decree). So the myth of the word hashishin (an Arabic word in a non-Arabic speaking country at the time) for “those who use hashish” to describe so-called drug using by the Assassins to glimpse the promised lands of heaven seems far fetched at best. It isn’t the oddest story though.
According to Marco Polo (who was collecting these rumors in the 1200’s, more than a century and a half after the Assassins took power, and likely affected by rumor and speculation), Hassan would drug potential members of the Assassins, bring them to a secret garden filled with wine, comfort and nubile women (as well as boys, depending on the telling) and leave them there for a day or so. Then the potential recruits would be drugged again, and brought back out and told they had been taken to heaven and would return again if they did Hassan’s bidding. This is of course understandably reasonable if one is in a hashish-induced daze, but sober people likely wouldn’t buy that story, and most militaries have to be sober to be truly disciplined and effective. Since Marco Polo tended to write down his stories complete and whole (some of his other tales about the East are even stranger than this one), what we likely are getting here is the Middle Eastern equivalent of wild speculation about the Free Masons in Victorian London.
Of course the fearsome reputation of the Assassins has transcended the group’s demise. It was their political agenda and killings (very similar to modern terrorist methods and dogmas) that gave the name an enduring feel in language. Since the Crusades were still happening, the facts of the Assassins deeds were inflated to rumor, and the rumor became myth as it transcended the long trek back to Europe where it was fed into the grist mill of the Middle Ages propaganda machine. The group eventually became a major bogeyman, and the legends of horrible, brutal deeds done by terrible, “godless” men to the pure knights and others in the area marked many murderers, and especially those who politically motivated, as bearing kin at least in name to the Assassins of such ill repute.
“Etymology of Assassin,” by Anonymous at Alamut
“Who Were the Assassins and the Old Man of the Mountain,” by Anonymous at Big Site of Amazing Facts