Medieval warfare is important for fantasy writers, at least up to a point, because they’re writing things that are often medieval in tone, and great wars are par for the course. Of course, there are some unique issues to consider (dragons, wizards, strange magical artefacts that can win the whole thing but have been left with curiously few guards at the bottom of a hole in the ground) but the basics are pure medieval warfare.
Or are they? I’d like to suggest that a lot of the things people see as intrinsic to medieval war, such as big battles, knights charging with lances, kingly generals, and so on aren’t always accurate representations of what happened in the past. They used to be seen as them. I remember reading some older books on medieval warfare (1950s) that had taken some of the more ‘literary’ accounts at face value, with the result that they were talking about million strong armies made purely of knights clashing on the open field. Things change though, and there are elements you need to be aware of if you’re writing fantasy warfare.
First, you need to understand that big battles were actually quite rare. They’re memorable, but they didn’t come along too often. The campaign to take England in 1066 had just three main battles (Fulford, Stamford Bridge, Hastings), and that was in an early period where castle based warfare wasn’t as prevalent, meaning that open battles were more likely. Longer term, a lot of the game for a medieval general was to avoid battle through retreat into fortified centres until they could be sure of victory.
That meant that the primary action of a lot of central medieval warfare was the chevauchee (which I have almost certainly mis-spelled there) or armed raid designed to spread terror in another’s lands. The goal was twofold. First, it drove villagers towards major population centres, increasing pressure on them in terms of food. Second, it made rulers want to come out to defend their lands, in theory at least. It was a way of avoiding the trouble of a siege, because many sieges in the central middle ages weren’t that successful.
When you did get a battle, it wasn’t just about the knights. Medieval writers tended to leave out the archers, for example, because they weren’t of the same class, while foot soldiers tended not to get a look in. Yet if they were so insignificant and ineffective, why did some cheats take whole units of footmen with them to the tournament field? Why did they bring them to the battle at all? Even knights quite often dismounted when they arrived at a battle that seemed to require it.
As for the ways armies were run, well, the notion of a clear command structure was a bit fanciful in most cases. It happened where there was a clear chain of homage from major figures down to underlings, but so many times, armies were pieced together from bits given over by supporters, who each took charge of their own bits. One of the major challenges for the medieval leader was getting everyone to show up on time and do what they were supposed to.
So there we are. There aren’t many things above, but hopefully, it’s enough to ignite your interest in the real way battles went in the period.