Fantasy worlds are never just fantasy. They appeal to us because they refract our own histories and speak to contemporary interests.

If there's one thing everyone can seem to agree on about George R.R. Martin's bloody behemoth of a book and television series, it’s that the setting is “medieval fantasy.” Martin's publisher bills his work as “set in an age of knights and chivalry.” Articles about the HBO adaptation explore the "real events from medieval history" that inspired the plot. When the series is criticized for its violence, treatment of women, or willingness to ice beloved characters, rejoinders from Martin and his defenders often amount to “that's just what life was like in the Middle Ages.”

There’s one problem with all this: Game of Thrones isn’t medieval. And it’s the non medieval features of the series that help explain its enormous popularity.

Let’s survey Martin’s world. Seven large kingdoms, each with multiple cities and towns, share a populous continent. Urban traders ply the Narrow Sea in galleys, carrying cargoes of wine, grains, and other commodities to the merchants of the Free Cities in the east. Slavers raid the southern continent and force slaves to work as miners, farmers, or household servants. There is a powerful bank based in the Venice-like independent republic of Braavos. A guild in Qarth dominates the international spice trade. Black-gowned, Jesuit-like “Maesters” create medicines, study the secrets of the human body, and use “far-eyes” (telescopes) to observe the stars. In King’s Landing, lords peruse sizable libraries and alchemists experiment with chemical reactions and napalm-like fires. New religions from across the sea threaten old beliefs; meanwhile, many in the ruling elite are closet atheists. And politically, in the aftermath of the Mad King and Joffrey, the downsides of hereditary monarchy are growing more obvious with every passing day.

These phenomena all belong to what historians call the “early modern” period—the timespan between the voyages of Columbus and de Gama at the end of the 15th century and the French and American Revolutions at the end of the 18th. A world that actually reflected daily life in the High Middle Ages (12th-century Europe) would be one without large cities or global networks. A diversity of religions would be inconceivable. Many aristocrats wouldn’t be able to read, let alone maintain large libraries. And no one would even know about the continents across the ocean.

What Martin actually gives us is a fantasy version of what the historian Alfred Crosby called the Post-Columbian exchange: the globalizing epoch of the 16th and 17th centuries. A world where merchants trade exotic drugs and spices between continents, where professional standing armies can number in the tens or hundreds of thousands, where scholars study the stars via telescopes, and proto-corporations like the Iron Bank of Braavos and the Spicers of Qarth control global trade. It’s also a world of slavery on a gigantic scale, and huge wars that disrupt daily life to an unprecedented degree.

There are a lot of reasons why this isn’t immediately apparent, of course. Westeros has no gunpowder, cannons, or printing presses. And Martin himself has explained that his fictional conflict between the northern Starks and southern Lannisters was inspired by the War of the Roses. Although it happened in the 15th century, this dynastic battle between the Houses of York and Lancaster is sometimes described as the final medieval war. And after all, what about all the knights, suits of armor, and swords? Isn’t that medieval?

The answer: Not really.

Writing for Slate, Matthew Yglesias recognized that the technology on the show was more advanced than it seemed:

One's first instinct is to describe it as featuring a "medieval" level of technology since you have knights in armor, castles, no guns or cannons, and no printing press. But in other respects Westeroi technology is much more advanced than the technology of medieval Europe. This is particularly true in the life sciences. Their "moon tea" appears to be a highly effective abortifacient or perhaps some kind of equivalent to our so-called "morning after pill." They also appear to understand a fair amount about the problem of infected wounds and how to treat them. This science is less advanced than post-WWII antibiotics but seems to be at-or-beyond 19th century medical science.

The fact is, though, that even the medieval aesthetics of the show owes a debt to the 16th and 17th centuries. As any scholar of the The Fairie Queene will tell you, Renaissance literature is replete with tales of chivalry, jousting, dragon-slaying, and magic. Writers from Spencer to Cervantes displayed and abiding fascination with these medieval tropes precisely because they were witnessing their demise. And our modern conception of the Middle Ages, which emerged out of the Victorians’ fascination with Neo-Gothic and Pre-Raphaelite aesthetics, was actually based upon these early modern retellings of medieval life.

So why, outside of dorky pedantry, does any of this matter? Because fantasy worlds are never just fantasy. They appeal to us because they refract our own histories and speak to contemporary interests. George R.R. Martin’s fantasy has grown to enormous popularity in part because of its modernity, not its “medieviality.”

Martin has created a fantasy world that chimes perfectly with the destabilized and increasingly non-Western planetary order today. And seemingly unwittingly, he’s brought a fairly obscure sub-discipline of academic history—the early modern world—to the masses.

To be sure, Martin partly retains a Tolkien-inspired dichotomy between lily-white good guys battling Orientalized hordes in the east—a perspective that contemporary historians, in my experience, find distasteful at best. But as Martin’s books progress, we find that his is a world where women and people of color struggle to gain leadership roles, where religious diversity (if not toleration) proliferates, where characters debate the ethics of abetting slave labor, and where banks play shady roles in global politics.

Sound familiar?