When I was a child, about 11 or 12, I was unfortunately subjected to a purported film known by the alias Brother Sun, Sister Moon, which claims to be a retelling of the life of St. Francis of Assisi. I’ve encountered more historical accuracy from 20-minute children’s cartoons, and I knew hardly anything about the history of the medieval Catholic Church at the time, so that’s saying something. (Though I should add that I was living in Italy at the time, not that far from Assisi, and St. Francis was and probably still is very popular there.)

The film was pretty much a retelling with a focus on a message more appropriate to the 1960s than the 13th century. Seriously, there are so many details it got wrong, and I doubt by sincere error, that any time I’m reminded of it I get a migraine. But today I shall embrace that pain, because one error in particular stands out as an example of today’s topic.

As a young man, St. Francis participated in a battle where he was captured and had a life-altering spiritual awakening. This is depicted in the film in such a way that I suspect the director intended the audience to be on drugs, but it’s accurate in broad strokes . . . very broad strokes. Yet even as a pre-teen, the armor the young Francesco wore drove me to distraction. It’s not just that it’s not accurate 12th-century Italian armor; at that age, I couldn’t have told you what was accurate, after all. It was that I immediately saw it was inaccurate because of the human factor.

This is the part of the film that I’m talking about. My apologies if my migraine becomes contagious:

As a know-nothing preteen, my immediate thought was, “If he basically can’t move in his armor, how does he fight? If his helmet has to be lowered by a pulley onto his head, how does he get it back on again later? If he can’t, what happens if he gets knocked off his horse?”

As an adult, it only reinforces my certainty that the director was on drugs.

This depiction of an early “knight” in armor (before plate became a thing on the battlefield) is heavily influenced by a later fad that medievals were so dumb they didn’t even realize how sealing themselves in proto-Killdozer armor was, y’know, a bad idea. This extended to things like health, superstition, and the belief that a medieval sword was too heavy to hold. Basically, if it was medieval, it had to be stupid, because medievals were stupid.

The reality is that the human species hasn’t changed. We are, on average, taller these days, but not because of any evolutionary improvement; rather, except for the poorest parts of the world, it’s no longer the norm that we go through cycles of feast and famine with the seasons, and so children have the opportunity for full growth uninterrupted by bad harvests or malnutrition. That’s it. Other than those extra few inches, people a hundred years ago were no more or less strong on average than people today; and they had the same mental capacity we had, along with the instinct that one should perhaps not unduly handicap one’s self when someone is looking to end your life.

This means the weight a soldier carries into the battlefield hasn’t changed for literally thousands of years. A Greek soldier at Thermopylae or Marathon carried roughly the same weight of equipment as a medieval knight, a WWII infantryman, or a US SEAL today. This is because there’s a certain point at which carrying more will make you more likely to die, and that kind of thing tends to lead to fewer soldiers on your side of the war. It doesn’t matter what your tech level is; if you can fight better without carrying it, then you’ll fight better than those who are carrying it.

I’ve seen this kind of thing pop up as an editor, usually focused on OMG sword too heavy, or shields make me drag my arm, or perhaps heroes only wear light armor and I know what light armor is because I play RPGs. I love tabletop gaming, but D&D has done more to perpetuate those Victorian historical errors than any other since, all in the name of game balance.

In reality, armor was extremely flexible, and the goal wasn’t to make you impenetrable but just harder to kill. Ironically, the gamer attitude of “learn to dodge, noob” is actually quite historical; armor was there to let you survive what you couldn’t dodge, and you trained to minimize impacts. Armor that didn’t let you dodge didn’t let you fight.

Here’s the best short video I’ve found on what’s possible in full plate armor:

This video uses a design and exercise regimen from a few hundred years after St. Francis, but it’s the kind of armor we normally think of as what a knight would wear. The person in the video is above average, but so would your typical medieval knight; and that knight would have been training since childhood for exactly this kind of activity. Perhaps not as single-mindedly as the knight who set that original regimen, but still far closer to it than most athletes today. So if this guy can climb a rock wall, so can a D&D paladin, thank you very much.

That kind of training is far greater, and started earlier, than that of modern soldiers, but that only underscores the same point. If you fight better without it, you don’t carry it. Guns make fighting easier, and so you don’t need to train from childhood to be effective.

There is a wealth of information out there these days on how arms and armor work, and what the lives of the people who used them were like. I recommend the History Hit channel on YouTube as a starting point; a lot of people will point to Shadiversity, but his focus on gaming (and willingness to post click- and rage-bait) makes his channel less useful as quick research for writers than a documentary channel like History Hit.

Above all, remember that what you describe should take into account the limitations of the people involved. Not just what they can’t do, but also what they can. Our ancestors weren’t dumb. After all, we’re descended from the ones who survived.