There are an infinite number of places to draw inspiration from for your DnD games, but with so much fantasy being inspired by the knights and knaves of the past it bears the question, how can we incorporate or draw inspiration from history? There are so many fascinating historical anecdotes and narratives, but there are also smaller things like methods of worship, architectural styles and fashion that we can draw upon. So, let's examine how to incorporate history into your DnD games.
1. Names
Have you ever had the issue where your players forget every NPC's name? I have. One potential way to make a name more memorable is by having that character be named after a very famous historical figure, even if they are completely different from that historical figure. Name the local blacksmith Caesar. Name the priest Adolf. Another thing to note is that, while the real world often conforms to naming conventions (such as Roman names normally ending in -ius), in a fantasy world there is no such need for conventions if you don't want there to be. There can be, but there don't have to be.
2. Fort and Castle Designs
Kings and lords of the ancient world were incredibly worried about invasion, for good reason. If you're stuck in a rut of creating square castles with towers on the corners and a gate, history is a good place to look to get out of that rut. Forts and castles came in many different shapes and sizes, walls had different entries and moats came in and out of style. Even where a ruler would build their castle had great significance. For one fun example, the old Danish kings built their forts in a star shape because taking a single, narrow ray of the star was incredibly difficult, and if attackers attempted to breach in between rays the defenders on either side would automatically have them flanked (it's worth noting these forts were built late enough in history they never saw action). Also, you should be putting enemies on your spiral staircases, as they were originally used not for spacial efficiency but because they were easier to defend.
3. Leader Motivations
I have found myself on many occasions asking, why is this king doing the things that this king is doing? Some reasons that real life past rules have used are very fun. Caligula once attacked the ocean because he was beefing with Neptune. The pope had Michelangelo arrested so that one of his relatives could steal some of his paintings. Henry the Eighth separated from the Catholic church because he wanted to get a divorce (read: legally bang Anne Boleyn). In other words, your BBEGs or kings can and should still be people. They want to eat good food, drink exorbitant amounts of wine, look at expensive art, spit on the graves of their enemies. Some of them probably want their names on monuments or leave legacies that will never be forgotten, by any means necessary. Some want to be literal gods, because then they can eat and drink forever and as much as they want. But all of them should still have the urges and inspirations of real world humans to back up their decisions.
4. Myths and Legends
No fantasy realm is complete without the myths and legends that color it. But, in a world in which magic is real and the gods tread the land, what would a myth or legend look like? Well, keep in mind that ancient people did believe that gods walked amongst them, and they also often believed in magic. Additionally, many societies throughout history have similar myths. For instance, the legend of the sleeping warrior is persistent throughout history, in which a sleeping warrior is entombed to be awoken when the country is in desperate need. This legend alone has so many ways to be ported into DnD, from having an actual warrior that awakens to fight/aid the party, to having a quest to find and awaken the sleeping warrior.
5. Art
It may seem like a small thing, historically speaking, but ancient rulers cared a great deal about their art. It was the ancient form of our modern medias in many ways. People had their faces painted onto important figures, they worshipped through art, they paid huge sums of money so that their collections would be the most interesting. Whenever people care a great deal for something, it holds significance. In DnD this can mean using art to hold clues, show likenesses of otherwise mysterious characters, or be a motivator for theft/payment/enchantment. Sometimes PCs want gold, other times they want a city to build a statue in their likeness that will stand for a thousand years.
6. Narratives
Like I mentioned before, historical narratives vary wildly. There are big narratives, like the unification of countries, to small narratives like the taking of a strategically important hill in the midst of a war. If you're looking to play out nearly any story, and you want to do it with realistic characters, there's no better place to go looking than history. For the purposes of DnD almost anything can be reskinned to fit your setting. Alexander's conquest and methods merely need a different name and can be slapped into almost any world. The betrayal of the tyrannical Julius Caesar can play out anywhere that a dictator has usurped governmental power. If you want to justify an isolationist empire look to the history of Japan. If you want to figure out how nomads of steppes would live look to the ancient middle east. Inspiration will always be lurking in the pages of the past.
I love history and think it provides fascinating anecdotes, stories and inspiration. That doesn't mean it's always easy to figure out how to use history, or even to find something applicable for your game, but I have little doubt that inspiration is there somewhere. Hopefully something here is in some way helpful, or inspiring. If not, feel free to email us and let us know your thoughts on how to improve!