The Order of Assassins was a group so feared, and whose reach was so far, that its very name became synonymous with murder for political means. While most of their history was lost with the fall of their strongholds, we do know some things about the order, its founder, and the actions of its followers. And while they didn't invent parkour (at least not officially), they were certainly the auteur geniuses who came up with using the constant threat of knives in the dark as a way to keep a populace in line.
The Origin of The Order
The Assassins were a small, splinter sect of hard-line fundamentalists created by a former Nazari Ismaili missionary named Hassan-i-Sabbah. While there's no telling at what point Hassan began collecting his followers, and training them, the first recorded instance of the order's activities was when they infiltrated the castle at Alamut, and took it over with no blood being shed.
Once the order had clamped its iron fist onto a remote, mountaintop stronghold where it was safe from attack, and where maintaining a siege would be extremely difficult, it began to spread its tendrils into the surrounding countryside. The network grew as more followers were recruited, trained, and sent into the world to act as spies, informants, and when necessary, enforcers. In fact, what made the Order of Assassins so feared was that their members looked just like anyone else. They would go unnoticed for months, sometimes years, getting positions in a target's inner circle and earning someone's trust. Often, assassins would disguise themselves as servants, playing the role to the hilt. Then, when the order was given, they'd draw a dagger and sink it into the target's back. Often they'd do it in broad daylight, martyring themselves as long as it meant the target they were assigned also died if there was no other way.
In many ways, the Assassins were similar to Japan's ninja (who have some bizarre facts of their own).
What Did The Assassins Do?
As a group of religious fundamentalists, the followers of Hassan had objections to the way their country was being run. Those objections were primarily with Seljuk Turks, who ruled large parts of what had been Persia, as well as with other, more permissive branches of Islam. As such, the group sent messages from the shadows, giving the impression that they could be anyone, anywhere, and making it clear they expected their wants and desires to be what guided public policy, and the way laws were both made and enforced by the government. When they were denied, targets who were considered to be acting against the interests of the order were killed in what would become the organization's trademark method.
The Order of Assassins focused mainly on political targets. Viziers, caliphs, and all manner of officials wound up with daggers in their backs as a clear message from the agents of the order. This went on for hundreds of years, until roughly 1219 when the Mongol Empire trod large sections of the Middle East under their elite cavalry's hooves. The order pledged loyalty to the Mongols, and for the most part were left alone. Or at least they were, until 1250, when the current Khan turned his attention to the Middle East after he had conquered Baghdad. The assassins planned to attack the current Khan, who was the grandson of the great Genghis Khan, but they were turned away.
That was the beginning of the end. The Mongols laid siege to the group's mountain stronghold, and forced the leadership into surrender. Once that happened the rest of the group crumbled. Several of the strongholds were destroyed, and in the year 1256 those who had once been the brains of the deadly organization were taken into the mountains, and killed.
And after that, supposedly, the Order of Assassins was no more.
The Legacy of The Assassins
The Order of Assassins were driven, disciplined, and brutal in a way that set the standard for groups throughout history. Their methods were effective, but deemed dishonorable and underhanded by many of their detractors. In time, their name became a phrase you would use to insult your enemies, claiming they were no better than liars, spies, and deluded murderers. It wasn't until even more time had passed that the group's name became synonymous with politically-motivated killings, which is an association we have to this day.
The society left us with more than a quirk of language, though. Its use of force and fear in order to bend the will of governments is, in a very real sense, alive and well today. Suicide bombers can do hundreds of times more damage than a single, driven man with a dagger, but the principles of the approach are clearly related.