Sometimes rambling about on the internet can suddenly turn into a trapdoor-like sliding descent into troubling oubliettes, usually involving some sort of conspiracy perpetrated upon the common man by an all-powerful secret cabal.  Who the cabal is, precisely, changes depending on the day of the week and the amount of crazy in your coffee, but it ranges from government black-suited spooks to dread Illuminati-infested secret societies.  

But whoever is pulling the puppet strings, surely this is a modern problem, right?  It must be the byproduct of a world where we’re bombarded with information from all sorts of sources, many of which aren’t reputable.  Not to mention having tons of free time that with which to let the pattern-recognition parts of the brain run wild. 
Apparently not, actually.  Even as early as the Middle Ages, well-meaning people have seen shadowy societies in the darkness, plotting the overthrow of all that was good and kind.  They just had cooler names.
Like assassins.  
Now, depending on your interests you may have heard different versions of the how the term assassins entered our vernacular.  One of the most common is that they were a group of people in the holy land who objected to the crusades.  Supposedly Muslim, they pledged that they would free themselves of the Christian infidels and consumed large amounts of hashish in order to be stronger in battle.  They became known as hashashin, or hashish eaters, which eventually found its way into English as “assassin.”
This ignores the point that Muslim fundamentalists wouldn’t have been allowed to take drugs.  Or the fact that hashish isn’t necessarily known to be potent as a battle drug.  
Prepare for battle!
 Another variation on the same story tells us that hashishins actually were servants and guards of the Persian Al-Hasan ibn al-Sabbah, who ruled a mountain stronghold that he would occasionally use as a prop in his after dinner entertainment.  To show how fanatically loyal his soldiers were he would order a guard or two to jump the 1,000 feet to his death… sometimes as an after-dinner trick, sometimes in front of invading armies just to show how powerful he was.  
Sure thing boss!
But how did he obtain this loyalty?  Apparently he rewarded his soldiers with beautiful women and with an incredibly potent form of hashish that they became dependent on.  It was apparently a hallucinogenic, potently addictive drug and gave them strange strength as well as keeping them under Hasan’s thumb.  Because of their addiction they became known as hashishins, even though they called themselves Nizaris.  Marco Polo himself reports that they often took the drug before leaving on missions they were unlikely to survive.  
The real story?  Well, it’s a lot more boring.  It’s important to remember that the Middle East was as fragmented back then as it is today.  Just because two people were both Muslim didn’t mean they necessarily agreed with each other and many sects and areas had feuds with their neighbors or differing sects. 
We all love our neighbors
 The word hashishi (the plural form of which is hashishin) doesn’t relate to hashish at all.  Rather it’s a term of abuse meaning either “low-class rabble” or “people of loose morality.”  Most linguists believe that the original assassin tale was invented by the Sunnis to disparage Hasan’s sect.  When the Crusaders reached the area they pieced together stories that they had heard, gossip about the strange practices of the others in the area, and created magnificent legends about the cult of assassins that they took home with them to Europe. 
And when the Crusades started going badly, as they quickly did, a secret society of deadly assassins was a great excuse.  How could they possibly compete with crazed drug users who were willing to throw themselves off cliffs at the mere whim of their lord?
I’m on it!
While it is possible that a cult of assassins did exist (Hasan was, after all, a real person and the Nizaris existed as well) most of the stories that we have about them are based on legends or written by those same confused Crusaders who just couldn’t figure out why they couldn’t take over the Holy Land like they had planned. Even if they did exist, it’s unlikely that they gained strange powers from hemp, or spent most of their time in drugged-out ecstasy… if only because Hasan’s army was an impressively sized one and it’s incredibly difficult to keep that many people suitably drugged for any length of time. 

But, however unlikely it was that Hasan or his army actually partook of hashish, his name has become associated with the idea.  When Rimbaud wrote in Matinée d’Ivresse, “Voici le temps des assassins” (“This is the time of the assassins”) he meant that he was experimenting with the drug.  It doesn’t help that Hasan’s last words were supposedly, “Nothing is true, everything is permitted.”

In the end, though, it’s not very likely that there was a secret, shadowy group orchestrating the conflict from behind the scenes. There were armies, some big ones, some with stronger warriors, better weapons, or superior tacticians.  There were even some really talented individuals.  But a secret cabal?

Nope.  Just a conspiracy theory 1,000 years before the term was coined.