Canon and Cannon: Military Revolutions in Medieval Europe and Westeros

By Ken Mondschein

If there’s a single thing that defines real-life medieval warfare, it’s the castle. If there’s a single thing that defines warfare in Westeros, however, it’s dragons—and with the upcoming prequel series House of the Dragon, we can expect the great scaly beasties to be front-and-center. What most viewers don’t realize, however, is that dragons in Westeros parallel the development of real-world warfare—and also provide a realistic explanation of the perpetually medieval setting of George R. R. Martin’s fantasy world.

Let’s start with why castles were so important. Warfare is really about controlling territory, and a castle or fortified town is an ideal means of doing so. To an invading medieval commander, the castle can best be conceptualized as a large stone Pandora’s Box containing various nasty things that can hurt you. The first and most obvious thing it contains are implements such as arrows, hot oil, and rocks that can be shot at, dropped on, or otherwise lobbed at your men. This makes a castle somewhat like a porcupine: A frontal assault is likely to hurt you more than it.


However, if you decide to leave the castle alone, the second thing a castle contains are soldiers. An unreduced fortress can be a major pain in the rear echelons, particularly when its garrison sallies forth to cut your supply lines. The third thing a castle contains is prestige—a weapon more abstract than a rock hurled from a trebuchet, but no less harmful in the long run. A castle is not just a fortified dwelling—it’s also a seat of government and justice. It is, in other words, a symbol of authority. If your aim is to embarrass your foe, to overthrow his power and take over his lands, then leaving him in possession of his castles is tantamount to saying you’re no real threat at all.

From a defender’s standpoint, however, castles are a win-win situation. For one, they’re a surprisingly cost-effective way to control territory. Sure, they’re expensive to build, but that’s a one-time layout, and it’s not like your serfs are going to ask for overtime pay if you ask them to do the grunt work. Rather, it’s paying your soldiers that’s the problem. Medieval lords financed their lifestyles and paid for their wars by milking the surplus from a subsistence-level agricultural society. A field army is very expensive, since troops need to be fed, armed, and paid. Tax systems were inefficient, and it’s also hard to convert the chickens, grain, and forced labor that your peasants are paying you into armor, horses, and coin.


Accordingly, medieval armies tended to be assembled when needed, quickly dismissed, and much smaller than later armies. A fortress and its associated territory, however, could be held by a fraction of the men needed for a field army. It was also why individual lords had so much power—so long as they had a castle, they could frustrate even a royal army’s attempts to bring them to heel.

In the real Middle Ages, the invention that ended the superiority of the castle was the introduction of gunpowder in the late fourteenth and early fifteenth centuries—not because it could shoot through plate armor (early handguns were far inferior to crossbows) but because cannon could blast through even the strongest fortifications. Since castles and fortresses were no longer an effective means of controlling territory, a commander’s only alternative was to give battle. Now, the side with the larger army had a definite advantage. With the new larger armies and need for sophisticated artillery, warfare became much more expensive. Soon, only great lords could afford armies, and natural evolution favored those political organizations that could collect enough tax revenue to finance armies large enough to compete on the battlefield.

Thus, modern states were born, with the king at the top of the social pyramid, assisted by his ministers. The minor nobility, for their part, became the officer class in these armies. Historians call this process “The Military Revolution.”

In a case of parallel evolution, Westeros had a military revolution of its own—only instead of cannon, it had dragons. Harren the Black, the vain, proud ruler of the Riverlands, serves as an object lesson of what happens to those who bring a castle to a dragon fight. Harren had just completed Harrenhal, the largest and grandest fortress in Westeros, when Aegon the Conqueror landed with a small army, his sister-wives Visenya and Rhaenys, and their three dragons. “And King Harren learned that thick walls and high towers are small use against dragons,” as Old Nan told the Stark children. “For dragons fly.”


Westeros had skipped right over the Age of Gunpowder to The Age of Air Superiority. Seeing Harren’s fate, the kings of the Stormlands, Westerlands, and Reach chose to give open battle and were destroyed, while the North, the Vale, and Oldtown peacefully submitted. Only the Dornish successfully resisted through guerilla warfare and were later brought in through marriage—and, much like Wales or Scotland, maintain a very distinct and nationalistic cultural identity.

The “Dragon Revolution” in Westeros had some of the same political effects that the Military Revolution had in Europe: Aegon the Conqueror unified six of the Seven Kingdoms into one centralized nation-state (Dorne was only pacified later) and established a capital and central government at King’s Landing, with offices such as Master of Coin, Master of Laws, Master of Ships, and Hand of the King.

However, things did not proceed exactly as they did in real life, where political organization progressed to centralized states with the nobility subjected to the king. One reason is probably because the Targaryens were Valyrians, which no doubt led to a certain discomfort with enfranchising the stakeholders in the kingdom, as had been done in the ancient Freehold of Valyria. Of course, Westeros is also very large and it made sense to deputize the leading families to aid in rule—thus the traditional titles of Warden of the North, South, East, and West.


However, the real reason for Westeros’ political stagnation is probably the nature of their ultimate weapons. Dragons are unlike cannons in one important aspect: No amount of money can buy more. There is little point in assembling an enormous army if dragons can incinerate them all, and no way to make yourself even more powerful by buying more dragons. Thus, with no incentive to modernize, the economy and tax system remained locked in a medieval mode of production. After all, even the most capable finance minister is of only limited use when the basis for your power lies between the jaws of an enormous, fire-breathing reptile.

Ken Mondschein is a scholar, writer, college professor, fencing master, and occasional jouster. Ken’s latest book is On Time: A History of Western TimekeepingClick here to visit his website. You can also fellow Ken on Twitter @DrKenMondschein

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Top Image: House of the Dragon: Photograph by Courtesy HBO