The movies often cast knights as villains, of course, but generally we have this idea that being a knight meant you lived according to some sort of moral and ethical code. Sometimes this is mistaken for Chivalry, which wasn’t exactly a moral code, but in general we have the idea that knights were noble warriors committed to serving their lord.

But as Lessons from History makes clear, being a medieval knight didn’t require any sort of moral code. What it required was money—and lots of it. Armor, horses, and weapons were incredibly expensive, so knights would find ways to align with wealthy aristocrats who would subsidize their knighthood. In exchange, the knights acted as thugs, putting down peasant rebellions, going to war with their lord’s enemies, and dealing out violence on demand. And as Today I Found Out notes, many poor knights lived with their masters and worked as bodyguards or ersatz police. And when these knights were set on the largely unarmed and disorganized peasants, they were often cruel, brutal, and unnecessarily violent.

That unnecessary violence often spilled out in unwelcome ways, especially as knights found themselves with nothing to do in-between wars. In fact, as History Today notes, violent knights wreaking havoc wherever they went was one of the motivating factors behind the Crusades of the 11^th and 12^th centuries. It gave the knights something to do aside from terrorizing the population—and thinned out their ranks a little at the same time.

Knights were expensive—their armor alone cost an enormous amount of money, and that doesn’t take into account the horses, weapons, and other equipment. And knights took years of training and practice to make. Knights were the core of every medieval army, but wars require a lot of warm bodies. Knights weren’t the only people on the battlefield. As the Metropolitan Museum of Art explains, just about every facet of medieval society was drafted into the war effort—city officials, peasants, and craftsmen often comprised militias, and in addition to mounted knights you would have archers, infantry, and pikeman out in the field. And in addition to all those non-knights, each knight also had a retinue of pages, squires, and other attendants who handled their horses, equipment, and other logistics.

And most of these people wore armor, because if you’re going to be standing around on a battlefield with arrows buzzing by and people swinging swords at you, it was kind of necessary. The term “men at arms,” in fact, exists to distinguish a non-noble from a knight; in practice they looked more or less identical. Armor was available to anyone who could afford it, steal it, or make it themselves.

Watch enough films set in the Middle Ages (or enough “Game of Thrones”) and you might think that the body count of knights must have been pretty high. And it was—but not as high as it could have been, because there was money in not killing people.

War History Online explains that medieval warfare was a pretty expensive business, and the lords who engaged in them tried to pay themselves back. One way they did this was to capture knights of noble lineage (i.e., knights whose families had some cash) and hold them until their family paid a stiff ransom. Sometimes the knights were even released in order to raise the money themselves.

According to BBC News, the system of ransom was very well established, and saw even ordinary soldiers seeking out high-value knights on the battlefield, knowing they could be traded for huge sums of money. One warrior claimed to have been captured and ransomed 17 times. The whole system was so advanced there were established rates for different ranks of prisoners and established systems of sharing a ransom among a unit. In fact, the development of rules surrounding knights and others being held for ransom in the Middle Ages laid the foundation of modern concepts of prisoners of war and their treatment.

“Game of Thrones” and “The Lord of the Rings” trilogy aren’t meant to be documentaries, but it’s easy to watch the epic battle scenes in them and come away with the impression that the mounted knight—gleaming in their armor, swords held aloft—were the most important and essential part of the medieval army. The fact is that while mounted knights were important, they were just one tool.

As author Mackenzie Kincaid points out, while a charge by mounted knights was certainly intimidating, a disciplined group of infantry would actually have little trouble repelling them as long as they had spears or other long weapons. In fact, knights rarely rode their horses into battle, because mounted cavalry charges were only used in very specific situations, and horses were expensive. As time went on and the longbow was perfected, the mounted knight became even less important.

In fact, History Collection notes that at the Battle of Agincourt—one of the most famous battles in medieval history—five out of every six combatants was a longbowman, and the rest were largely dismounted knights. Cavalry could be incredibly effective in the right situations, but mounted knights were never as important or as commonly employed as movies and TV shows make it seem. It’s just that thunderous cavalry charges by armored knights are cool.

You’ve definitely seen this in a movie about the Middle Ages: The hero wades into battle and begins hacking and slashing at their armored foes. And every single warrior they hit with their blade goes down screaming. Despite wearing armor all over their body. The movies always depict armor as being essentially useless, because all you have to do, apparently, is get a good slash in with your mighty (and supernaturally sharp) sword and the enemy goes down.

Which leads to the question of why people spent so much money to acquire and wear armor if it was so useless. The answer, of course, is that it wasn’t useless at all—as noted by Tales of Times Forgotten, it worked incredibly well. Science ABC notes that specialized weapons were developed over the years to make armor more vulnerable, like the stiletto, designed to slip between the seams of armor. But more commonly knights would resort to bludgeon-style weapons—hammers, maces, or even the hilts of their swords—to try and concuss their enemies or at least knock them down, at which point they could be more easily stabbed to death with the aforementioned stilettos.

According to Outdoor Revival, crossbows could be effective against plate armor, as the powerful bolts could actually pierce metal. But only if the crossbow was fired from relatively close range. Generally speaking, plate armor worked much, much better than the movies want us to think.