The more I write, the more I feel that “Oh, but it’s a fantasy world! You’re not actually depicting any real cultures” is not at all useful or productive. For one, if you can’t see the connection between something like Lord of the Rings or A Song of Ice and Fire and medieval West Europe, I don’t know what to say to you. They are not direct depictions, but they are very, very evidently rooted in history and culture—and the baggage that comes with them.
It’s true that the connecting fibres are much thinner for some works than others, but while most are certainly not on the scale of Middle-earth or Westeros, many follow in that kind of tradition. In my day job (such as it is), I study the early Renaissance in western Europe along with the eighteenth and nineteenth centuries in Britain, and those interests constantly pervade my fiction. I did as much historical research for the first chapter of The Timewalker as for straightforward historical fiction, because most aspects absolutely are drawn straight from history.
At the same time, of course, it is a fantasy and a secondary world, and those are never going to be directly analogous.
For instance, ASOIAF is obviously and unabashedly inspired by the Wars of the Roses, enacted across a continent rather than one small island, but the Starks and Lannisters are not simply fantasy versions of the Yorks and Lancasters. During the Wars of the Roses, both families were Plantagenets, branches of the royal house of England with rival claims to the throne. In ASOIAF, neither the Starks nor Lannisters have any direct claim to the Iron Throne at all—that would be the Targaryens, the deposed and periodically-insane royal family (~Lancasters) vs their Baratheon cousins (~Yorks) who won the previous phase of the conflict.
The Baratheons’ ebullient warrior-king, Robert, is most comparable to Edward IV and his beautiful, ambitious wife to Elizabeth Woodville. However, Cersei Lannister is altogether a wilder, more amoral figure than Elizabeth, and Robert marries her out of political expediency rather than Edward’s passion for the unsuitable Elizabeth. Also unlike Elizabeth, Cersei triumphs over the austere northern lord who would strip power from her and her children, where Elizabeth lost the immediate battle to Richard of Gloucester—a far more ambiguous figure than noble Ned Stark.
In character, Cersei is much more akin to the Lucrezia Borgia of legend if not history, complete with an ambitious, highly intelligent father who ruthlessly uses all the children (Tywin Lannister/Alexander VI), an incestuous brother-lover locked into an order that denies him his inheritance (Jaime Lannister/Cesare Borgia), and a second, widely loathed brother (Tyrion Lannister/Juan Borgia). Even that isn’t perfect, though: Cesare’s strategic and administrative brilliance goes to Tyrion, Lucrezia’s overriding loyalty to her family at odds with a burgeoning conscience to Jaime, and Juan’s incompetent, wild recklessness to Cersei.
As far as Wars of the Roses analogues go, Daenerys Targaryen’s place draws nearest to Henry Tudor, Earl of Richmond, the future Henry VII. Daenerys and Henry are, respectively, exiled survivors of the deposed branches of the royal family (Targaryen/ Lancastrian) who, with local and foreign support, return to reclaim the kingdom. Yet Daenerys is wildly dissimilar from Henry. Even her claim to the throne differs. Where Daenerys is the only surviving, legitimate child of the old king, Henry claimed royal heritage through a bastard line, and had a prudent, restrained personality in general, more like—say, Jon Snow.
That’s ASOIAF. If you jump to Lord of the Rings, we have Gondor, very obviously interpreted (and meant) as a take on the Byzantine Empire in its decline. Like the Byzantine Empire, Gondor is the surviving half of a once-towering empire, holding on while the other half (Arnor/Holy Roman) loses its territory and decays into little states and feuding communities. The Battle of the Pelennor Fields has striking parallels to the fall of Constantinople, and Tolkien directly referred to Minas Tirith as a take on Constantinople. Yet again, the parallels are not 1:1, even setting aside the basic fact that it turns out completely differently. Denethor is at most a tragic inversion of Emperor Constantine, but even that seems a stretch. His sons Boromir and Faramir don’t plug into any particular historic figures, and the loyal, Germanic-influenced Rohirrim don’t seem to fit into the Byzantine model at all.
Gondor is also heavily inspired by late medieval/early Renaissance Italy, complete with internal strife and ruling princes who have total discretion about sending armies to the
Pope Steward to defend Rome Minas Tirith. Tolkien insisted that the rejuvenated Gondor at the end of LOTR is not Northern European, but essentially a restored Roman Empire with its seat at Rome. He identified various areas of Italy as the RL counterparts to Gondor: Venice/Pelargir, Assisi/Lossarnach, and almost certainly Naples/Belfalas. However, Gondor is geographically far larger than Italy, large enough to extend to Greece and Turkey, with influences from ancient Egypt (monuments, mummification, religious practices).
Neither of these, of course, are perfect models of reference—though at least you can legitimately argue that casting Anglo actors as Aragorn, Boromir, Denethor, Faramir, etc wasn’t actually accurate to “Tolkien’s vision.” But these are probably the most recognizable models with strong connections to history, and even with those the references are multilayered and flexible.
Essentially: this particular genre of quasi-historical fantasy absolutely draws from RL, sometimes closely, sometimes less so, which makes it perfectly possible to talk about accuracy, appropriation, and so on, in the context of fantasy. At the same time, it’s complicated by the fact that references are never direct and are worked out in the context of their own stories.