Alexis Carew: Justified by the second-wave Earth colonies having been settled by individual nations, instead of trying for melting pots as happened in the first-wave colonies only for them to instead fall apart in sectarian warfare.
New London is the simplest one, essentially early 1800s Britain, complete with tons of colonies where they tend to dump people with troublesome ideas rather than tolerate, reeducate, or fight them.
The Republic of Hanover is a stand-in for Napoleonic France in the Horatio HornblowerIN SPACE!verse, but culturally has more in common with Bismarckian Prussia and Nazi Germany (culturally and linguistically German, with a manifest destiny attitude towards rulership of mankind), with a dose of the Soviet Union.
The Grand Republic of France Among the Stars (the French Republic for short) is essentially the French Third Republic with the stylings of the Bourbon monarchy (with bureaucrats and civil servants standing in for the nobility in the ballroom). They also take historical cues from the pre-World War II United States, friendly with New London and opposed to Hanover, but militarily neutral.
There is also a second Space Germany, Deutschstirne, which Hanover bloodily broke away from centuries ago in a war that led to the passage of the Abbentheren Accords to govern interstellar warfare. Hso-Hsi, Space China from the sound of it, has so far only been briefly mentioned by name.
In Patrick Tilley's Amtrak Wars the Mutes are clearly First Nations while the Iron Masters are basically Steam PunkSamurai.
Arc Of Fire: Kajin is one for China, going by the names of its people and customs like using chop sticks. It even has the equivalent of Buddhist monks. It seems probable Mohender Gosh's home country is one of India, judging by his name and culture.
Piers Anthony's Bio of a Space Tyrant: the Earth nations have colonized the Solar System - North and South Jupiter were colonised by N/S America respectively; Mars = Arabs; Saturn = Asia; Uranus = Europe etc. They develop Hyperspace travel and plan to colonize the Galaxy by constellations: USA get the Eagle, Russia gets the Bear, China gets the Dragon.
Lois McMaster Bujold's Chalion universe does this: Chalion, Ibra, and Brajar make up the analogue of the Iberian peninsula, Darthaca is France, the Weald is the Holy Roman Empire (and used to be Gaul, or at least somewhere with Celts), and Roknar plays the role of North Africa (despite being an archipelago). To conceal this slightly, everything is set in the Southern hemisphere, with all the geography flipped north-for-south. Bujold even manages to have the Roknari's religion differ from that of the Chalionese despite this being a world with Physical Gods.
Well it's a heresy actually, although from the Roknari's point of view it's the other way around. The Roknari are actually more like traditional Christians in that the Bastard is their Satan while the other nations see him as performing a useful purpose.
Cook's The Black Company novels start light while the Company is in the north, then runs with this trope when they get to Taglios. Gunni are copy-and-paste Hindus, Vehdna are close to Muslim, and the whole pluralistic, pacifistic culture is what could have happened if the two religions and smaller sects had to join together or die. Painfully. In the name of a demon-eating goddess their gods are afraid of. Even later on, Hsien (China) gets tossed in there too.
Elantris features several Fantasy Counterpart Cultures, though there's a bit of mix-and-matching going on. The Fjordell Empire occupies a political position similar to Rome, but is culturally and linguistically more Nordic, with a religion that seems equal parts Islamic and Catholic. The nation of Teod (of which one main protagonist is princess) is very obviously England- a small island that is nonetheless regarded as a great power due to its very impressive navy and canny leadership. The nation of Jindo, mentioned often but never seen, seems to be a stand in for medieval China. The nations of Duladel and Arelon, on the other hand, don't really seem to have any real-life counterparts.
The Alloy of Law has the Roughs, which are an equivalent of 19th century The Wild West. There are small towns inhabited by people who've had enough of city life (and laws of civilized societies), lawkeepers who hunt bandits for bounties, and savage koloss as a fantasy equivalent of Native American tribes. Even fashion is very Wild West-like, with long dusters and hats. Elendel itself is more like London at the height of British imperialism.
Per Word of God, Scadrial (where all the Mistborn books are set) is intended as this as a whole. Everything is as close to Earth-like as possible. Gravity, environment, and time are all the same. Technology mostly matches up with real-world progression (though the Final Empire caused more than a little Schizo Tech), and cultural attitudes are the same. The Survivorist religion parallels Christianity very closely, the primary difference being that they believe their martyr became divine after death rather than before.
Warbreaker: Hallandren has a number of similarities to India, most obvious in their dye exports and religion that other countries find weird at best and heresy at worst. Per Word of God, the setting originally came about in order to write a book set in one of those "far-off lands" in most fantasy books where the exotic goods come from.
Most of Eastern Roshar in general is inspired by Asian cultures, but only in general terms. Fashions are similar, and their strong caste system brings to mind the old Asian cultures, but little more than that. Interestingly, all eastern Rosharans have Asian epicanthic folds (the "narrow eyes"), though other than that their races don't resemble Asians at all.
Funnily enough, the people of Shinovar look mostly European (since they lack the epicanthic folds) and live in the only area of the continent with normal plants and animals, but their culture resembles Buddhism crossed with Shinto animism. Other than that, however, there is little resemblance.
The Herdazians resemble Hispanic cultures, as they are a minority everywhere, have their own slums and slang, and are generally ignored by everyone else. They also resemble Jews in a few ways (most notably their mothers), but they aren't known for any association with money.
In Terry Pratchett's The Carpet People the Dumii are clearly the Roman Empire.
Roger Zelazny's The Chronicles of Amber claims that every world in existence exists in Shadow, as a reflection of the True World, Amber. Hence, several cultures of Earth are pointed out to be reflections of some part of Amber (and several famous historical figures are said to have been trained by the long-lived Amberites).
The titular culture of P.C. Hodgell's Chronicles of the Kencyrath has a LOT of Jewish parallels, being the Chosen People of a very strict God who have Temples and Books of Law; furthermore, they're exiles and nomads. Their religion emphasizes obedience to the Law over faith, and their God isn't all that nice. A number of Kencyr have Hebrew-influenced names, the protagonist among them (Jamethiel, with the Hebrew -el "of God" ending). Aspects of their culture, though, have other influences; their honor code and ritual suicide traditions, and martial arts have some Japanese parallels, while the segregation and hiding behind masks of Highborn women draws comparison to Islam.
Chronicles Of Magic has the Falians, or "people of Fa"— a country a lot like ancient Japan whose inhabitants are beautiful, dark-skinned people with snow-white hair and ruby-red eyes.
Calormen, in C. S. Lewis' The Chronicles of Narnia, is Middle Eastern with Ottoman/Turkish influences, with a specific takeoff on the ancient Carthaginian religion as a plot point. Notably, the Calormenes are explicitly pagan, not monotheists—their religion is not a fantasy counterpart of Islam. (The Calormens are descendants of European pirates-turned-castaways and their Polynesian wives/concubines/sex slaves, but how long they have been in Narnia is never stated.) The Film of the Book of Prince Caspian plays up the Telmarines' difference from the Narnians by making Telmarine culture clearly influenced by that of medieval Spain, apparently supposing the original pirates to have been Spanish. Also invoking images of Conquistadors that are familiar to US viewers but wouldn't have occurred to Lewis or his English readers.
It's also fun to go through Pierce's Circle of Magic series trying to determine what each culture is based on. For example; Imagine Tris as an English girl. Good luck imagining her habitual snark in anything other than an upper-class British accent. Emelan itself is probably based more on Italy than England, given its Mediterranean climate, focus on trade, and diverse population (Italy having handy trade routes with Africa and the Middle East).
The Yanjing Empire is definitely based on ancient China, and the Namorn Empire is based on Russia. Also, the city-state of Tharios has a government like Ancient Grome, while the caste system there is based on Japan, with the yaskedasi (entertainers) similar to the geisha of Japan and the prathmuni based on the burakumin. The food and weather that Emelan and some of its neighboring countries have is Mediterranean, and Chammur is more Middle Eastern/Arabic.
The Traders seem to have a lot of similarities with the Romani (nomadic people that are quite separated from other cultures as a defense against huge amounts of discrimination, etc).
In The Cinder Spires by Jim Butcher, humanity lives in towering arcologies called "spires". The main setting is Spire Albion, a constitutional monarchy and major naval power where all the characters have distinctly British names and are fond of tea. Spire Albion's archrival, Spire Aurora, appears to be based on the Spanish Empire.
The Citizen Series: The Cutter Stream is late colonial America (specifically the mid-Atlantic states beginning around the time of the French and Indian War), sparsely populated and featuring Merchant Prince-style social stratification. The Riders are Space Nomads that stand in for the Native Americans. In theory Brasilia and Terra represent respectively Hanoverian Britain and Bourbon France but they're essentially interchangeable (the only major distinction is that the Cutter Stream was colonized from Brasilia).
In Codex Alera, the Aleran society is based on ancient Rome, using Roman terminology, system of government, and military structure. It turns out that there's a reason for this: they actually are descendants of a Lost Roman Legion that ended up falling through a Negative Space Wedgie that transported them to Alera, although this point is not mentioned much in the books. Despite this, Aleran society has notable differences from actual Roman society, primarily in that their military is even more professional and organized than historical Roman armies, and there's an absence of real religion in Aleran society. Also, thanks to the Elemental Powers that all the Alerans possess, they have Magitek that allows them a standard of living comparable to the 1950's. However, like the Roman Empire, Alera's biggest problems are not external threats but their own crippling internal problems.
Robert E. Howard's stories about Conan the Barbarian, where the countries of the Hyborian Age are transparent stand-ins for real-world nations or peoples. Examples include Stygia as a stand-in for Egypt, Shem as Israel, Aquilonia as Imperial Rome, and Iranistan as... well, guess. (Note, however, that these are supposedly nations that existed in the history of our own Earth, pre-continental drift theory and pre-mass migrational theory, so the similarities to the civilizations that they would eventually evolve into is doubtlessly intentional.) His favorite grey-eyed morose heroes are all supposed to be ancestors of modern Celts. A folk etymology for Cymru (Wales) is attributed to the Cimmerians (Conan's people) while the name Conan is Irish.
If you look at the map of the Hyborian Age◊, this becomes even more obvious. Aquilonia is about where France is, Cimmeria is where Scotland will someday be etc. Howard in fact wrote a history in which the beginning of modern European and Middle Eastern races are set out.
The nation of Jackals in Stephen Hunt's The Court of the Air and The Kingdom Beyond the Waves is a Steam Punk version of Victorian England, although they have a much less reverent attitude towards their royalty (this is because they went through their version of the English Civil War, only the democracy stuck). It's hostile neighbor, Quatérshift, is a take on Revolutionary France with the Terror turned Up to Eleven. Cassarabia is an Arabian caliphate, with the worship of an immortal god-king replacing Islam. Catosia, with its warm climate and warring city-states, suggests a matriarchal Greece (and in particular Sparta), the Lashlites vaguely resemble Native Americans despite living in the equivalent of the Scottish highlands, Mechancia is something like Switzerland but inhabited by robots, Kikkosico seems to be Russia. The Southern Forests serve as Darkest Africa, Concorzia and Isla Verde seem to be Latin America, the Polar Barbarians are probably Vikings, and the Black Oil Horde seem like Diesel Punk Mongol hordes. There's also an extinct Mayincatec civilization that's dominated by a Religion of Evil worshiping monsters that turns out not to be not so extinct after all
The Crimson Shadow: Eriador is pretty clearly a parallel for Scotland, with one of its famed heroes being one Bruce MacDonald, who has the city Caer MacDonald named after him. Avon stands in England, with cities such as Newcastle and Carlisle which match actual English cities' names. Gascony is a clear parallel to France, not only with the pseudo-French names and having the name of a historical French province, but also its history in regards to people from there having invaded Avon (England) in the past. All three also share the same relative locations. An island near both may be the stand in for Ireland, though we don't get much information on it. Isenland stands in for Iceland, with its people being raiders like the vikings. Eriador and Avon also seem to follow a counterpart Christianity, though with no Jesus figure.
While The Hundred, the central culture in Kate Eliott's Crossroads trilogy doesn't seem to be based on any particular culture the Sirniakan Empire is very similar to the Ottoman Empire, and the Qin are very Mongolish with some Japanese samurai added in while the towns of the Golden Road they conquered seems very Chinese and the Silvers are reminiscent of Jews.
The Hundred has a lot of Pacific Islander influence.
Speaking of Kate Eliot, her epic Crown of Stars series is basically a What If? Europe, with a viking culture made up of Lizardmen, amongst other differences. Two particularly interesting facets, DaisaniteChurch has a female pontiff called a Skopos (Greek for purpose) and that the British Isles expy is ruled by powerful Druidic witches.
In general, the biggest difference between the world of Crown of Stars and Earth's medieval period is that it's much more, for lack of a better word, female-friendly in general- almost all cultures are either gender-equal (with men still holding the bulk of military power, but women dominating religious roles and political leadership open to either) or matriarchal, and the one completely patriarchal nation doesn't really factor into the plot. This probably has something to do with the fact that early humanity was guided and taught by the Bwr, a One-Gender Race of all-female centaurs.
The big What If? here is that their religion, which is otherwise extremely similar to Catholicism, is based on a god that is both male and female. This change echoes throughout every aspect of this middle-ages-inspired setting, and for the most part explains why the world seems to be devoid of institutional sexism. It seems to have been replaced, with intense class hierarchy serving as the main social conflict.
In The Dagger and the Coin, the area of the world in which the plot is set is pretty clearly a fantasy counterpart of Europe, although some of the countries have easier to find parallels than others:
Antea is very clearly Germany.
Asterilhold is, by extension, Austria.
The Free Cities are the medieval Italian city-states; Vanai in particular is, paradoxically, a combination of Venice and Florence.
Herez and Cabral seem to be Aragon and Castille, although which is which is difficult to tell, given how little we've seen of either.
Birancour has elements of both France and Belgium.
Northcoast, likewise, seems to have elements of both France and England. It may seem peculiar that the holding company of the Medean bank, which sounds like it must be based on the Medici bank, is based in Northcoast, instead of in one of the Free Cities. It becomes clear in the fourth book, however, when Cithrin invents central reserve banking, and transforms the Medean bank into the fantasy counterpart of the Bank of England.
Hallskar seems to be Scandinavia generally.
Sarakal and Elassae are somewhat harder to pin down, as is the Keshet. The Timzinae, who are the primary population of both Sarakal and Elassae, play the part of the Jews to the Anteans' Nazis, but there are no really obvious parallels between Timzinae and Jewish culture.
The Dragon Empire, of course, was the Roman Empire.
The Honor Harrington series is based on this trope, since its pretty much the Napoleonic Wars in space. Some are blatantly obvious, while others are little vague. Much fun can be had by history buffs trying to match up the Honorverse star nation with their historical counterpart. A few more obvious examples:
The Star Kingdom of Manticore itself is pretty much Britain in the 1800s, minus the empire (although it does become an empire in later books). They have a monarchy and active aristocracy coexisting with a democracy. Its three planets, Manticore, Sphinx, and Gryphon, correspond to England, Wales, and Scotland (especially that last one). And it's a mercantile superpower.
The People's Republic of Haven is France in the late 1700s. It starts off as essentially pre-revolutionary France with a veneer of democracy. Then it undergoes its own revolution, run by a Committee of Public Safety, which is led by a man named Rob S. Pierre. And its capital city is named Nouveau Paris. Eventually, it becomes a genuine democracy modeled on the modern United States, and drops the "People's" part from its name.
The Andermani Empire is explicitly based on Prussia - its founder, Gustav Anderman, believed he was the reincarnation of Frederick the Great. The Empire's official language is German, although most of its population is ethnically Chinese, so you got names like Chien-lu Anderman.
Grayson admits that it's Meiji-era Japan, complete with katanas. However, its actual cultural background is the Deep South.
Subverted in the case of Masada, which has a lot in common with Taliban-run Afghanistan (veiled women, strict religious laws, and a government composed entirely of religious fanatics)... except that the Masadans first appeared in Honor of the Queen, published in 1993, and the Taliban only came to power in 1996.
Weber himself compared the Kingdom of Torch to 19th-century Haiti following the slave uprising there, only more stable and backed by several major powers.
The one surefire aversion is the Solarian League, which is far too big for any historical parallel. Weber once said "If the Solarian League is the United States, then Haven and Manticore might as well be individual counties in California".
Weber's later work the Safehold series is set nearly 1000 years after humanity started a Lost Colony and had the project heads disagree about how deep the Space Amish needed to go. The winners implemented a religion designed to prevent technology that would attract the Scary Dogmatic Aliens that destroyed the rest of humanity. The conflict over this results in a religion very similar to Medieval Catholic Christianity. In addition, the main setting is The Kingdom of Charis, a (relatively) progressive and free-thinking island nation, with a powerful navy; it is visited by the protagonist, a cyborg copy of the executive officer of the colonists' escort fleet, who disguises herself as a man named Merlin, and greatly strengthens and enriches it, including establishing something very similar to Anglicanism. There is also the Republic of Siddarmark, comparable to the Austrian Empire in function and culture, Charis is England, Emerald is Ireland, Chisholm is Sweden, Corisande is France, and Harchong is comparable to China. (It is a large feudal empire, famous for fine silk, and gunpowder was (re)-invented there.) At one point in the first book Charis is explicitly compared to late-Renaissance/early Industrial Revolution England or Holland.
The map of the Eleven Kingdoms looks like a rough approximation of Northern Europe. Imagine Ireland and the UK are attached to the continent, so that The English Channel is a broad estuary; Scandinavia is a simple vertical coastline sans Denmark; there's no Italy or Greece or Mediterranean visible. The analogues to modern nations would be something like Cassan/Kierney/Transha/Claibourne = Highland Scotland, Meara = Lowland Scotland, The Connait/Howwice = Ireland, LLannedd = Wales, Gwynedd/Carthmoor/Corwyn = England/The Netherlands/Germany, Bregmagne/Fallon/Fianna = France, Torenth = Hungary/Russia/Belarus, Tralia/The Forcinn = The Levant (Lebanon, Israel, Syria, Jordan), R'Kassi = North Africa (Algeria, Morocco, Libya, Egypt, plus Arabia).
Culturally, the regions and their inhabitants as depicted in the text match their real world analogues; R'Kassi horses are famous, as is Fianna wine, while people from the Cassan/Kierney/Transha/Claibourne region wear tartans, speak with broad Scots-like accents, and have a clan system and tanistry (elected leadership within the clan). A version of Catholicism sans the Papacy prevails in the west, with Eastern Orthodoxy prevailing in Torenth, Islam to mostly to the southeast and a Norse paganism in the far north.
Politics tends to follow some of the real conflicts of medieval Europe. Particular attention is given to the rivalry between spiritual and temporal authority, including disputes over the benefit of the clergy. Such conflicts are sharpened by the Deryni persecutions within Gwynedd; Church authorities forbid the powers as evil, yet foreign kingdoms (including Gwynedd's main rival Torenth) have no such compunctions. The Haldanes' solution is to claim their Deryni-like powers are different and a sign of divine sanction, though it plays as a distinction without a difference.
Justified (or perhaps averted) in the Deverry novels by Katherine Kerr, where the main society isn't a counterpart to Gaul; they are Gauls, transported to a fantasy world to escape the "Rhwmanes".
Same thing with the Scottish society in Kate Forsyth's Witches of Eileanan series.
Justified in Dinotopia. The various cultures on the island were influenced by shipwreck survivors who brought their way of life with them. Also inverted by others who made it off the island. The second book states that the Egyptians were influenced by such people.
Much of Discworld is like this, generally using it to satirize the original culture. Überwald is Transylvania (and Eastern Europe in general), Genua is New Orleans (with a bit of Disney World), Brindisi seems to be a mix of Spain and Italy, Klatch is the Middle East and North Africa (while also being a stand-in for any "generically foreign" place or concept), Howondaland is a mix of sub-Saharan Africa and Central/South America, and the Counterweight Continent is part China, part Japan (especially the late Edo period). Llamedos is Wales, Djelibeybi is Ancient Egypt, and Ephebe is Greece. Pseudopolis and Tsort are Athens and Troy. Lancre is rural England with a dash of the Appalachians and a Scottish lean, Quirm seems to borrow a lot from France and Italy, and Ankh-Morpork has been described as a cross between eighteenth-century London, nineteenth-century Seattle, and modern New York. The dust jacket for The Last Continenthung a lampshade on this; after mentioning the continent of Fourecks, it had a footnote saying "Which has nothing to do with Australia. At all."
The Empire (of the Counterweight Continent) keeps out foreigners by building a huge wall across the border. (It doesn't work, but then it's really there to keep the people in, so they don't notice outsiders aren't invisible vampire ghosts [i.e. Gwai Lo].) By and large, the Agatean Empire's approach to foreign policy was to pretend the rest of the Disc didn't exist. This is pretty close to Imperial China (as well as pre-modern Japan; the Empire is both).
The paperback edition of The Last Continent has it as a foreword, adding that it "just happens to be, here and there, a bit... australian" [sic]
And the Nac Mac Feegle are cartoon Celts with permanent woad.
And the Tezumen in Eric are clearly the Aztecs/Mexica.
Even New Zealand gets a look-in, recast as the Foggy Islands, and to add to the list of British Empire And Commonwealth Dominions, there are several vague but cumulatively telling hints here and there in the Discworld canon that point to there being a "South Africa" on the Disc, no doubt turned Up to Eleven with biltong occupying the dwarf bread culinary niche and memories of a past war involving Welsh soldiers and a people not completely unlike Zulus (A Llamedosian regiment is said to have distinguished itself at a battle of "Lawkes' Drain"...)
So far, the only distinctly recognisable part of the United States to have made it into Discworld is the Mississipi River (The River Vieux) and the Delta, serving as an all-purpose Deep South/Louisiana, with creole language and cuisine, riverboats, voodoo, and witch-queens overlying a superficially-Disney magic kingdom called Genua. Up to Eleven, naturally.
Red Indians (Native Americans) exist on the Discworldnote Ref. One-Man-Bucket, the spirit guide to Mrs Cake in Reaper Man but are assigned the rolling prairies of central Howondaland — the proto-Mid-West is transplanted to the Discworld Africa. note The Complete Discworld Atlas creates a massive region, marked as empty wilderness on the previous Mapp, called "The Great Outdoors" and populated by those who fled their previous homelands due to famine, poverty, and political or religious persecution. "Tired and huddled masses" are explicitly referred to. This has created a loose asociation of different ethnicities and language groups who get together to trade and buy and sell from each other. The people are characterised by independent bloody-mindedness, a hatred of excessive government, the right to carry whatever weapons they bloody well like, and in the case of the extreme Omnian schismatics who harvest salt around a salt lake, polygamy and abstinence. Hmmm.
A version of Ireland has been conspicuous by its absence in the books but Unseen Academicals mentioned the very Irish sounding 'Great Bronze Spoon of Cladh' so perhaps one exists and will appear someday. note The Complete Discworld Atlas has a detailed map of the Disc in which it is revealed that Llamedos in fact has a border region where place names such as Cladh betray a more Gaelic rather than Welsh etymology. If a Discworld Ireland exists, it is in the outlying fringes of Llamedos where the people and the spoken language become strange and unintelligible even to the "Welsh".
In the Drake Maijstral series by Walter Jon Williams, the Khosali, one-time conquerors of Earth, are modeled on the British Empire. Very proper, very strict, very formal, very prudish (in their alien way)—very Victorian.
The Nadir, especially their portrayal in Legend, are basically Mongols and their leader a Genghis Khan Expy.
The Chiatze are very strongly based on Imperial China (but with samurai-equivalents thrown in).
The Sathuli have a lot of Muslim/Arab cultural features.
The Fremen from Dune are pretty obviously based on the Bedouins (and on a lesser extent, the Bushmen) while Caladan has a strong Greek/Spaniard flavor (the Atreides bloodline is supposedly descended from Agamemnon). The Fremen are descended from Arabs, but ironically their wanderings before arriving on Arrakis resemble the Jewish Diaspora (of course, the same could be said about the Palestinians, so it's not too far off...). The political system of the Galactic Empire itself is pretty strongly modeled on that of the Holy Roman Empire, with Persian, Byzantine and Ottoman influences mixed in. The backstory for the novels makes it clear that many core elements of these cultures have been preserved across dozens of centuries, and even justifies this by attributing it to Genetic Memory.
The Fremen religion is a cross between Islam and Buddhism. The name "Zensunni" is used a lot. Also, the Orange Catholic Bible - clearly, radical Protestantism and Catholicism have merged.
And the tidbit about their crysknives needing to draw blood before being sheathed used to be said of Nepalese kukris (though Gurkhas probably didn't take it as seriously as the Fremen), maybe explaining the "Zen" part.
The prequel Butlerian Jihad books make it clear that the Agamemnon from whom the Atreides line descends was NOT the historic Agamemnon, but rather a fictional future-cyborg-warlord of the same name. Don't think it's explicitly stated anywhere that this Agamemnon is himself descended from the historic one. Of course, as the prequels were written by Frank Herbert's son, this interpretation may diverge from what the original author intended.
The implication is in the name. Agamemnon and Menelaos are collectively referred to in The Iliad as the "sons of Atreus" or, for short the Atreids. Then again, Herbert indulges so heavily in Future Imperfect (according to the history of the setting the first Padishah-Emperor was Alexander the Great, and Washington was the name of the first noble house to use atomic weapons in war) the two may very well have gotten conflated somewhere along the line.
When Fritz Leiber's heroes Fafhrd and the Gray Mouser get lost in Ningauble's caves and emerge on Earth, their personal histories and memories are altered appropriately. Fafhrd is, not surprisingly, now Scandinavian, and Lankhmar is replaced by Alexandria. The real reason for this is that "Adept's Gambit" was an early story Leiber had written prior to creating the his world of Nehwon, and he later used the "Ningauble's interdimensional caverns" gimmick to shoehorn it into canon.
The unnamed kingdom in Delia sherman's The Fall of Kings is clearly based on late 17th-early 18th century Britain with the North and South standing in for Scotland and England respectively. There doesn't seem to be an analog for Wales. Kyros is meant to be Greece, more specifically Crete.
Joe Abercrombie's The First Law has a huge country called The Union, which rather resembles the Holy Roman Empire. Much of the action takes place in the province of Angland, where the characters fight against the Celt-based Northmen. The Old Empire, a ruined former powerful empire, resembles the Roman Empire down to names and architecture.
The Commonwealth in Book of the New Sun is modeled on the Byzantine empire, but very obviously set in South America, with references to mate and pampas, as well as a stand-in for Lake Titicaca.
Viron, in Book of the Long Sun, is also vaguely "Latin," with the city's ruler being called "Calde" and the state religion being a parody of Catholicism (with some minor details changed: it's a polytheist Catholicism that practices animal and occasionally human sacrifice.) The rival city of Trivigaunt is a gender-swapped fundamentalist Arabia. Both of these are justified in the story the builders of the Generation Ship wanted to send a range of human cultures into the universe, all of which would worship the Monarch and his family as gods
In the Gentleman Bastard series, there are several. Camorr is obviously Venice, with its canals and Italian-sounding words. Vadrans seem to be modeled on Germans/Slavic people (tall, blonde, famous for alcohol production). The old Therin Throne sounds similar to Rome (it even fell to the Vadrans!) and there are several other city-states with differing cultures, as well.
Teresa Edgerton's Goblin Moon and The Gnome's Engine do this intentionally, being set in a 'Euterpe' that's a close fit to 18th century Europe, and incorporating such parallel nationalities as 'Spagnards', 'Imbrians', and 'Nordics'.
Karen Miller's Godspeaker Trilogy has a number of these. Mijak is based on the Hittites and Summerians. Etherea has elements of Medieval England. Thzung-tzhungchai is clearly based on China (Haisun probably too, but we never get to see any of it) and Arbenia and Harbisland have very definite German traits.
John Norman's Gor series actually explains this in the backstory: the humans are literally descended from ancient people from various Earth cultures brought to the eponymous planet by aliens. Specifically the main human culture is based on Greco-Roman and there are knockoffs of Vikings, Inuit, Sub-Saharan Africans, Arabs, and others around the fringes.
Jonathan Swift's Gulliver's Travels has multiple, most noticeable the countries of Lilliput and Blefuscu being satirical stand ins for 18th century Great Britain and France respectively.
Most of Guy Gavriel Kay's books make heavy use of this trope, and are centered in a counterpart to a specific region of Europe:
The Darkness Series has an interesting take on this trope. The series is essentially a fantasy version of World War II. So, every nation taking part in the series fills the role of a power from the war. However, physically, culturally, and linguistically, these nations are also something of a mix-and-match of various world cultures. Algarve plays the role of Nazi Germany, but its people are Scots-Irish in appearance, and their language is based on Italian. Another good example is Kuusamo, which fills the role of the United States, but is populated by Finnish-speaking East Asians.
In the Videssos Cycle, Videssos is closely modeled on the Byzantine Empire, and neighboring states are likewise based on the Byzantine Empire's neighbors.
The political situation in the Tales of the Fox series is inspired by post-Roman Britain, with Elabon as Rome, the Trokmoi as the Celts, and so on.
Jaida Jones and Danielle Bennett's Havemercy and Blood Magic are set in the nation of Volstov which is very similar to late 18th-early 19th cent. Russia minus guns and plus Magitek but with the geography reversed so that it's capital is close to the border of the rival Ke-Han Empire which itself is an amalgam of Manchurian China and Samurai Japan, especially the latter.
The continent of Elbador, a continent being settled by the Orkish Empire can be similar to South America, complete with an Amazon River and rainforest while Panadyssia, a colony of the Sylvan Commonwealth has a lot in common with Australia, including an Outback, Uluru and hostile wildlife.
The Hunger Games: Panem is a futuristic, sci-fi version of Rome. The country's name is an adoption of Rome's "Bread and Circuses" motto - panem et circenses in Latin. The Capitol is an incredibly authoritarian superpower that brutally reigns over conquered territories to feed the decadent desires of its own citizens. The gladiatorial parallels with the Hunger Games are obvious, of course. Parties at the Capitol feature guests who induce vomiting so that they can consume more food, which is popularly thought to have been common at Roman banquets. The Capitol residents' first names are almost all from Roman historical figures.
As a bit of extra Genius Bonus, the lottery slips that entitle the residents of the districts to free food (at the cost of increasing their chances of being reaped) are called Tesserae. In Ancient Rome, the Tesserae Frumentariae are tokens handed out to citizens of Rome which can be exchanged for free grain. In the districts, bread and circuses come in a single package.
There are also 13 districts ruled over by a distant authority, not unlike the 13 Colonies that would some day become the modern United States of America.
Averted and played straight in the Inda books. The Venn are clearly based off the Vikings, but that's because they are Vikings, or at least are descended from a bunch of Vikings who crossed from our world to Sartorias-Deles. Their distant descendants, the Marlovans, have a completely different culture that presumably developed after they split away from the Venn. Other nations and cultures within the world have no clear Earth equivalent, having been in the world and developed away from Earth for long enough that they no longer resemble whoever their initial progenitors were.
Glen Cook's The Instrumentalities of the Night series takes place in 12th- or 13th-Century Europe and the Middle East, except with the names (and some aspects of the religions) changed — and magic works. Most of the action takes place in Firaldria (Italy), the End of Connec (Languedoc), and the Grail (Holy Roman) Empire. The main character is a Sha-lug (Mamluk) from Dreanger (Egypt) sent to infiltrate the Chaldarean (Roman Catholic) Church and learn if they're planning another crusade against Al-Prama (Islam). Meanwhile, a cyclic shift in the forces of magic is bringing on an ice age much more severe than anything experienced in our history at the comparable time....
In Chris Evans Iron Elf trilogy the Empire is clearly based on the British Empire of Victoria although the tech level is about a hundred years behind. Likewise the Mashugeb lands are just as clearly northern Africa and Elfkynan is India under the Raj.
The Isavalta series is a rare use of a Russian fantasy counterpart.
The world of the Sulien novels features fantasy parallels of a whole bunch of Arthurian legend, with the island of Tir Tanager standing in for England and going on from there, down to Saint Patrick, Jesus and Arthur himself. Figuring out what the real world equivalents are is a great deal of the fun.
Tooth and Claw features a dragon society that matches very closely to Victorian England. Except, of course, that they're dragons.
The Kingdoms of Thorn and Bone series by Greg Keyes features this, most obviously the "good guys" countries, Virgenya and Crotheny giving very strong Britain-and-it's-territories vibe, Vitellio as a sort of Spaintaly (complete with the head of the Church based there), a variety of southern countries of Mediterranean-and-western-Europe inspiration (Safnia, Terro Gallé...) and the evil (well, from most main characters' perspective) northern Hansa with a Germanic flavor...
Indeed, it's implied and/or stated that those countries were mostly founded by the descendants of people from the corresponding regions of Earth.
The Kushiel's Legacy series by Jacqueline Carey features Terre d'Ange, which is France down to the language, and various other parallels - in one particularly egregious example, the Venice-counterpart is named "La Serinissima", a nickname by which the real city is sometimes called.
This was famously used in The Lord of the Rings, where the Shire is obviously based on the English countryside. This was fairly rare in J. R. R. Tolkien's works, though; most of his cultures were built by creating a language, and then a culture that used it. As he specifically notes in the case of Rohan, that their language was "translated" as an old form of English did not imply they were Anglo-Saxon in culture. Instead it was meant simply to maintain its position in the language family tree as regards to the Hobbits' tongue, which was translated as modern English.
On the other hand, the Rohirrim — as noted under Film above — are a sort-of Fantasy Counterpart Culture of Goths (or Gothic realm on Black Sea steppes to be specific), except perhaps with the Goths swapped for another Germanic group, the Anglo-Saxons.
The Southrons are dark-skinned horsemen and elephant-riders coming from regions in the south, while the Easterlings ride great wains or wagons. They do not correspond to any specific real culture and are meant to echo generalized outside threats to early medieval Europe, like the Huns.
Some Tolkien-inspired fantasies portray dwarves as Scotsmen, though Tolkien himself did not. The closest Tolkien came to this was noting the dwarves tended to have harsh, guttural accents when speaking the common tongue. However, Tolkien's dwarvish language uses triconsonantal roots just like Semitic languages such as Hebrew or Arabic, and in fact he explicitly tried to portray some aspects of the Jewish diaspora and culture in a fantasy setting. However, all Dwarvish names are Old Norse. (Though those are not the "real" names in Dwarvish, which are never revealed to non-Dwarves, but rather Norse names from the human cultures around the Lonely Mountain.) Those in The Hobbit are taken from the names of the first dwarves ever created, in Poetic Edda.
The ancestors of the Rohirrim have Gothic-style names (Vidugavia, Vidumavi), and they were involved in conflicts a confederation of Easterling horse cultures, probably mirroring the fourth-century clash of Huns and Goths.
Númenor, Tolkien's fantasy version of Atlantis, is not quite Ancient Egypt, but Adûnaic again mirrors Semitic languages in its general structure, and their advanced culture and later obsession with deathlessness, embalming, and grand sepulchral architecture makes it hard not to think of that. They even had a valley of rock-hewn burial chambers for their Kings and Queens, and names like Ar-Pharazôn do the rest to cement that association.
Lyonesse by Jack Vance has several: the aristocracy of Lyonesse seems to be vaguely Germanic, Dahaut is pre-Revolutionary France, and the Ska are based on the Vikings. Troicinet represents Britain. All of these are based not so much on modern images of these cultures as on representations from the 19th century or earlier (Troicinet is a sea power and balances the other nations; the Ska aren't noble warriors but fearsome and heartless raiders, similar to portrayals of Vikings in medieval English sources.)
Isle de la Lumiere, where Malediction Trilogy is set, seems to be an equivalent of 17th century France, as shown by the names of characters, their aristocratic titles, fashion, entertainment and weapons. Funny enough, the only character with an English name, one monsieur Johnson, is a foreigner and comes from the continent.
The continent of Osten Ard is closely based on Medieval Europe, even down to the languages and their names for the days of the week. Unlike most fantasy Europes, this one actually has a Christianity parallel (and not a Crystal Dragon Jesus one, either), although the many of the Rimmersmen (Scandinavians) and Hernystiri (Celts) still worship (or at least believe in) the "old gods" in secret.
Lampshaded in her SERRAted Edge series; most culture in the fairy world of Underhill was either transported there by visitors from our world, or copied by the fantastically imitative (but woefully uncreative) elves. In fact, to point out precisely which human-world culture (real or fictional) an elf ripped off is considered a huge insult by many of them.
The Joust novels clearly take place in two-kingdoms Egypt. In an afterward, Mercedes Lackey admitted that she was tired of medieval Europe and wanted to try something different, and that she'd planned to just set it in Egypt, but that amateur Egyptologists were so picky that she renamed everything to avoid complaints.
The Truwa tribe from Danish author Josefine Ottensen's Mira Trilogy are pretty blatant High Fantasy Jews. Mira's father is Truwa, and while you only become Truwa through the mother(Mira's mother is very middle-class and very white), Mira identifies strongly with the Truwa people. She eventually goes through a ceremony similar to a bat mitzvah, enraging her mother and putting her in grave danger, considering that the monarchy is planning to destroy all Truwa people (think the Spanish Inquisition).
Garth Nix's Old Kingdom books have the pseudo-medieval Old Kingdom — where magic works but most modern technology fails as you approach the border, where Necromancy is a day-to-day hazard — sharing a border with Ancelstierre — which is remarkably like World War I England (or possibly World War I Australia/New Zealand given the author's antipodean roots) to the extent that the Ancelstierre army are armed with .303 bolt action rifles, .455 revolvers, white phosphorous grenades and Lewis guns and on the Border use both this and their khaki uniform AND sword bayonets, Mail hauberk with khaki surcoats and enchanted spears because when the wind blows from the south (Ancelstierre proper) magic stops working, but when it blows from the North (Old Kingdom) technology fails.
Also the Ancelstierre Moot (Parliament), the Chief Minister (Prime Minister) who runs the government, the Hereditary Arbiter (King/Queen) who lives in a palace without whose blessing you can't form a government mentioned when the bad guys start a civil war and the fact that they haven't taken over the Palace means they haven't won, and the fact that Ancels-Tierre is from the same root (Angles' Land) as England (compare the real-life French word for England, Angleterre)... it's England all right.
Ancelstierre also has cultural/political parallels with early industrial Australia insofar as being a nation bordered by a seemingly alien land that the government does not understand and fears. Protecting the nation's border is a huge deal. Australia is slap-bang in the middle of the Asia-Pacific, and until the 70s feared and did not understand what they called the "teeming hordes" of Asia. Other political parallels are also present.
Continuing south from Ancelstierre we come across some other vaguely-European nations, a vaguely-Mediterranean sea and then a vaguely-Middle-Eastern region, refugees from which play a role in the third book.
Jane Yolen's The Pit Dragon Trilogy really goes for the gold on this. The entire series takes place on a planet that was once used as a penal colony. Almost all the main characters are descended from the original criminals, and generally have an inherent distrust of anyone who wasn't (all the criminals' descendants have a double K in their name — Jakkin, Sarkkhan, Akki, etc., so it's no secret who is who). The world is mostly great big deserts, great big mountains, and slightly uncivilized cities. Other planets keep trying to rule it and use its natural resources. The fact that the planet is named Austar IV is really just the icing on the cake.
RCN: The Republic of Cinnabar is a blend of 1800s Britain, minus the monarchy, with bits of Republican Rome (author David Drake remarks that there's a surprising amount of overlap). The Alliance of Free Stars is a stand-in for Napoleonic France, with elements of Prussia and the Soviet Union.
Arcasia is clearly inspired by France of the late Middle Ages, though it appears to be one that was built on top of an Expy of mythological Greece. The naming conventions reflect this (Count Bricemer is married to the Countess Pucelle, and their son's name is Acteon). Oddly, the people of Arcasia are generally depicted as being Ambiguously Brown, rather than Gallic.
Also, given their monotheistic fanaticism and penchant for torture, Spain during the Inquisition.
Tyris is a distant tropical continent that is currently being colonized by the Glyconese, who are enslaving its tribal inhabitants and forcing them to labor in plantations and mines. Sound familiar?
Raymond E. Feist's The Riftwar Cycle is set in an almost-England kingdom that's conquered and brought civilization to the majority of almost-Europe, although they occasionally have trouble with their almost-African desert-people neighbors to the south, and the Greek/Roman hybrid nation of Queg. (The almost-Africans are ruled by a "master race" caste whose parallels to the Egyptian dynasties are too blatant to miss.) The titular Riftwar involves an invasion across space-time by a warrior race of almost-Oriental people who the author says are based on the Japanese and Korean cultures, called the Tsurani. Other notable cultures are the somewhat Italian Kingdom of Roldem and the Hillmen, who are basically Scottish Highlanders with a vaguely Buddhist religion. Later books introduce analogues to Chinese and Native American cultures (if Native Americans were Aryan), among others...
Feist's take on the moredhel - dark elves - is quite consciously Native American - tribal, shamanistic, and resentful of humans for what they (with good reason, considering their life spans) see as aggressive occupation of lands that are rightfully theirs. With the human tendency to breed like rabbits and thus their advantage of numbers, pretty much the only reason the border to the Northlands remains where it is now is that the lands the moredhel now occupy are too cold and barren for humans to even want them.
The Rigante are essentially very Scottish Celts (and later, simply Scottish). The series also features counterparts of Romans and Vikings as well as, in the chronologically later parts, Native Americans, Cavaliers and Roundheads.
Monica Hughes' Sandwriter is set in a Middle East counterpart. With oil disputes.
Fairly obvious in Second Apocalypse. The Inrithi are the Crusaders (although their religion is more similar to Hinduism than to Christianity), the Kianene are Arabs, the Shigeki Syrians, the Nansur is the Byzantine Empire and the Scylvendi the Mongols.
The Silerian Trilogy: Sileria has many similarities to Sicily-feuding clans, powerful crime syndicates which extort and murder people, plus a succession of foreign rulers. Valdania, meanwhile, has a resemblance to the Roman Empire, and it also has the same geographic relation of mainland Italy to Sicily, plus it's religion may be a vague Christian counterpart-it apparently involves "the Three" with a "sign of the Three" and believers say "Three into one!" On the other hand, its priests sacrifice goats. The Moorlands mirror Britain somewhat. Kinto, however, does not appear to have a counterpart, though it has vague similarities with some East Asian nations.
In the broadest possible strokes, Westeros is western Europe. The Narrow Sea is a counterpart to the English channel. The western half of Essos is essentially the Mediterranean region note (Italy, the Balkans, East Turkey, North Africa and the Levant), while the Eastern half is the Far East. Separating them are the Dothraki Sea, which acts as a rough parallel to pre-Qing dynasty Central Asia, and the Bone Mountains, an analogue to the Urals. Sothyros is Darkest Africa crossed with the Savage South, while the Summer Islands are reminiscent of the classical Lost World, despite being well known and easily accessible, with elements of Neo-Africa. The Summer Sea and Basilisk Isles have some elements of the West Indes during The Golden Age of Piracy.
Westeros is one of western Europe as a whole, with the regions being the North (Scotland, especially beyond the Wall, which is itself analogous to Hadrian's Wall, which separated England and Scotland), the Iron Islands (Viking Scandinavia and Ireland), the Riverlands (the Low Countries), the Vale (the Alps), the Westerlands (England and Wales), the Stormlands (Germany), the Reach (France), and Dorne (Moorish Spain).
The Neck, the southernmost region of the North, is reminiscent of the geographic divide between Central and South America known as the Darién Gap. Much like the Neck, the Darién Gap's terrain is notoriously inhospitable, filled with wetlands, rainforests and plague; there is also a marked cultural divide caused by the region's environment, making construction advancement completely unfeasiblenote -The Darién Gap is the only point in America where the Pan-American Highway is interrupted.
The First Men are vaguely Celtic, especially with their influence from the Children of the Forest and their concentration in the north after the Andal invasion. The Andals are stand-ins for the Saxons, displacing the First Men in the most fertile regions and imposing their language. The Andals also have some Norman elements, with their new church and tradition of chivalry.
The Seven Kingdoms are a parallel to the Heptarchy, seven Saxon kingdoms that existed in pre-Norman England.
The invasion of the First Men through the Arm of Dorne (now a chain of islands) is similar to the theory of the occupation of the Americas through the Bering Strait, an ephemeral ice bridge between Kamchatka and Alaska
The manner of the invasion, a religion-driven pursuit, is reminiscent of the Crusades and the Andals painting the Seven-pointed Star in their shields is similar to Constantine I's army's adoption of the Christian Cross.
The Faith of the Seven is pre-Protestant Reformation Roman Catholicism, replacing the Holy Trinity of the Father, Son and Holy Spirit with the Father, Warrior, Smith, Mother, Maiden, Crone and Stranger.
The Iron Islands are stand-ins for Vikings, with their longboats and their habit of plundering resources from non-Ironborn ("We Do Not Sow"). They also have several Irish influences (the Vikings attempted to invade Ireland during the Battle of Clontarf), especially their generational hatred against the mainland oppressors.
The mountains clans of the North (The First Flints, the Wulls, the Norreys, the Burleys, the Harclays, the Liddles, and the Knotts) are reminiscent of Scottish Highlanders.
Dorne is a stand-in for Moorish Spain and the Mediterranean, although it also resembles Wales with its differing culture from the mainland and the way their rulers style themselves "Prince". The name of the main house there, Martell, comes from French, as does the name of Princess Arianne.
In particular, the Rhoynish in Dorne are analogues to the Moors in Spain; much like Moorish took a good half-century for the Spanish to defeat, the Dornish were incredibly difficult to conquer.
The Rhoynish Princes and Princesses of Dorne are a similar dynasty to the Macedonian Greek Ptolemaic Pharaohs of Egypt, a transplanted culture ruling over a desert land. Much like the Ptolemaics, the Roynish in Dorne have certain disposition to give special importance to the women members, the Princesses of Dorne, which would be the fictional equivalents to the Arsinoes, the Berenices and foremost, the Cleopatras who ruled Egypt.
Much like Dorne resisted the Targareyans for a hundred years, Wales resisted the Normans and successive English kings for over two hundred years.
The family names Lannister and Stark are thinly veiled references to the Wars of the Roses, a civil war in England fought between the houses of Lancaster and York. There are also similarities to the way the Scottish clans used to vie for power - the Lannisters are very Campbell-like. The Red Wedding was based on the Black Dinner, and there is even a place in Scotland called Wester Ross.
The Westerlands have aspects of Wales, from their geography and the fact they are an area largely based on mining and living in mountainous terrain.
The Free Cities are similar to the city-states of medieval Italy, and derive their languages and culture from the Valyrian Freehold, a Rome analogue. Braavos is even a City of Canals like Venice, although it is influenced by Amsterdam as well. Like Medieval Florence, much of its power comes from a powerful Bank.
In a more literal sense, the statue of the Titan of Braavos is the counterpart to the Colossus of Rhodes and of the Statue of Liberty, Braavos having been founded by people fleeing the Valyrian Empire.
The breaking with a major empire also associates Braavos with the League of Lombardy, cities that successfully battled against the Holy Roman Empire and included Florence.
The culture of Braavos, with its assassins and sword-fighting culture further associate it with Florence. Bravo is an Italian word, meaning "brave one". The theatre scene of Braavos is suggestive of the Renaissance era Florence (famous for comedies by Pietro Aretino and later, Machiavelli, who achieved popular success as a playwright rather than as a political theorist) and Elizabethan England.
The Rogare family of Lys, a wealthy banking family, may be partially based on the Medicis. The Head of the Family, Lysandro Rogare, was called the Magnificent, like Lorenzo Medici, and a woman of the family married royalty, the future Viserys II, like Catherine de' Medici, who married Henry II of France.
The conflicts over the Stepstones (a chain of islands between Westeros and Essos) are reminiscent of the conflicts over the islands of the Mediterranean Sea such as Corsica note -which was historically disputed between Italy and France- and Cyprusnote -disputed by the Greek, the Turkish and the British- and the territories in Gibraltar note -which have been disputed between the British, the Spanish and the Moroccans-.
The Tyrosh in the conflict for the Stepstones are reminiscent of the Turkish conflicts for Cyprus, specially for their identifiable symbolic adoption of the color red.
The Rhoyne river in Essos is reminiscent of the Nile River in Northeast Africa; much like the Blue and White Nile Rivers that are the main tributaries of the Nile, the Upper and Little Rhoyne Rivers are tributaries of the Rhoyne. The river-faring peoples of the Rhoyne are also reminiscent of the cultures of the Nile.
The Dothraki are clearly a stand-in for the Mongols and similar raiding tribes. They are a horse-centered, nomadic people who rule a vast grassland and can push around fortified nations with the threat of their mounted archers. Word of God has also cited influence from the Huns and the Sioux.
The Slaver Cities—Astapor, Yunkai and Meereen—closely resemble ancient Middle-Eastern empires such as Assyria and Babylon: they build pyramids/ziggurats and use slaves for manual labor or as soldiers.
Also, the former Ghiscari Empire is quite analogous to Carthage, to the point of having been brought down and destroyed by Valyria after 5 "Ghiscari Wars".
The city-states of Slaver's Bay's practice of raiding other peoples and bringing them back as slaves is reminiscent of the Barbary Pirate States. Astapor's "Unsullied" recall the Spartans in their equipment, tactics and Training from Hell, but they are also brainwashed eunuch soldiers for sale like the Mamluks and Janissaries.
The Unsullied warriors raised in Slaver Bay are reminiscent of the Mameluke slave cast warriors of North Africa, who were highly specialized slave factions used for warfare. Much like the early Mamelukes, the Unsullied are slowly gathering social status.
Qarth is a stand-in for Constantinople, with its geographic location in control of a sea pass between the east and west, great opulence and memories of ancient greatness.
Though the real deal were not actually confirmed to have had cultures, the Ibbenese are hominid alternatives equivalent to the Neanderthals in appearance, though they are as intelligent as normal humans; they mainly engage in a lifestyle reminiscent of Arctic Circle cultures, such as fishing, whaling and the consumption of blubber.
The rarely-mentioned Sothoryos is analogous to Africa and the South American Amazon. Sothoryi are another type of hominid, though they are more ape-like and more savage than the Ibbenese, resembling more to hogs and trolls; another possibility states that the Sothoryi are actually great apes or a sort of early hominid like a Homo erectus and that their descriptions are a case of Lost in Translation; still the Sothoryi are supposedly capable of talking and often communicate in the language of trade.
The Golden Empire of Yi Ti is based on imperial China. The Five Forts are enormous buildings that protect the Empire from intruders much like the Great Wall of China, though unlike the real deal the YiTish did not build the Forts, predating the culture for an unknown number of years.
The Lengii are a culture which is an offshoot of the YiTish which emigrated to the island of Leng, much like the Japanese originated from the mainland; like Japan, the Lengii closed their ports and shut themselves from foreigners for a great number of years until the Yi Ti were able to establish some trade with them after a war of conquest, on which the colonizing YiTish established themselves in another island and were later expelled completely by the Lengii, finally opening their ports.
Much like the Dothraki to Western Essos are the Mongols to Europe, the Jogos Nhai are the Mongols to China's perspective, which would be the in turn Golden Empire of Yi Ti. The Jogos Nhai are horselords as well, though they do not quarrel between themselves like the Dothraki; however, they are not less barbaric when it comes to war.
The town of Port Plunder in the Basilisk Isles is a settlement of pirates, slavers and debauchery in the style of the now sunken town of Port Royal in Jamaica; unlike Port Royal, Port Plunder is usually reconstructed elsewhere in the islands whenever the previous town falls.
The Free City of Norvos practices a more ancient, alternative version of the Andalic Faith of the Seven; it has customs reminiscent of both Judaism and Islam; whereas the Norvoshi religion exists, a fictional form of Satanism also exists as the prevalent religion of the Free City of Qohor, which the Norvoshi despise fervently.
The Valyrians are basically the Roman Empire with dragons. From their small peninsula nation they conquered a huge chunk of their continent and their form of government, the Valryrian Freehold, was the Roman Republic with the serial numbers filed off. Now (middle ages), though their empire is no more, their provinces stand as independent kingdoms and speak dialects derived from Valyrian on their way to become separate languages (like the Romance languages).
Dragonstone is thus analogous to Roman Britannia, as the farthest island outpost of the Valyrian Empire.
Dragonstone is also an equivalent to the Channel Islands, which are personal possessions of the British crown and were held by the Dukes of Normandy over a century before the invasion of England, similarly, Dragonstone was home to the Targareyans for over a century before Aegon's conquest.
There are also comparisons to be made with the Minoans, including the fact that they were apparently destroyed by tectonic activity and were based off a chain of Southern islands.
The Targaryen custom of incestuous marriage has some similarities to another aspect of the Macedonian Greek Ptolemaic Pharaohs of Egypt, who married brother to sister as well.
Also some analogy to Atlantis, especially with the "Doom of Valyria" destroying it out of nowhere.
The Targaryen conquest of Westeros mirrors the Norman conquest of England, but the Targaryens themselves also have some Byzantine trappings (ex. "wildfire", a green-colored version of Greek Fire). They are of Valyrian (i.e. "Roman") origin, too.
The Hightowers, vassals of the Tyrells have close ties and have been longtime patrons to the Order of Maesters and the Faith of the Seven. This closely mirrors the real life House of Medici of the Republic of Florence, both in their pursuit of the higher arts and knowledge, and in their contributions to the church; much like the Medicis of old who became Popes, for instance, there have been Hightowers who have become High Septons as well.
The Tyrells may be partially based on the Carolingian dynasty. The Merovingian dynasty that ruled France were eventually eclipsed in power by their stewards (the Mayors of the Palace), who ended up overthrowing them. The Tyrells are a family related to the ruling House Gardner, who are hereditary stewards of Highgarden. When House Gardner is wiped out the Tyrells are given control of Highgarden.
Word of God says that the planet it all occurs on is an alternate Earth.
The Ununited Kingdoms in Jasper Fforde's Song of the Quarkbeast is clearly meant to be a parody of the UK.
In The Sovereign Stone trilogy there are Japanese Elves, Mongol Nomadic Dwarves and Viking Orcs. The Humans in this setting are divided into multiple cultures resembling Medieval England (Vinnengael), Arabia (Dunkarga), Persia (Karnua) Africa (Nimran and Nimorean) and Celtic (Trevenici).
The Jedi were originally partially Jewish. The Starkiller trusted the secrets of the Force to his 12 children. Over time, one tribe of Jedi fell in with the Sith pirates, and the Sith now kill Jedi. Also, they had a prophecy about a savior (Anakin) and when they didn't believe in him, he went and found someone who would believe in him (Palpatine) and killed them all off. Also, being a Jedi is punishable by death under the Empire.
The Massassi are Mayans.
Corellians are based on Americans, though their disproportionately powerful Space Navy has vaguely British trappings as well.
Coruscant is based on the Biblical Tower of Babel. It's even Vongformed rapidly because of the sheer blasphemy (in the Vong religion).
In Stravaganza, 'stravaganti' are humans with the ability to teleport between Earth and a Fantasy Counterpart Culture version of Italy while asleep. The twenty cities of Talia are stand-ins for the most important Italian cities. When it's night in Talia, it's day on Earth and vice versa.
Fiona Patton's medieval Tales of the Branion Realm are set in an alternate Britain down to the map and the place names, with two opposing Crystal Dragon Jesus faiths - one is basically Continental Catholicism with a dragon thrown in, and the other has similarities to Celtic Christianity but is based around the four classical elements. The conflicts are inspired by the English conquest of Wales, the Scottish Risings, and the Hundred Years' War.
Tortall itself is medieval England—a feudal society with knights and vassals, a temperate four-season climate, English (ish) names, and a large territory.
Tyra is analogous to Renaissance Italy (republic, Mediterranean-like climate, trade economy). The Great Southern Desert is Arabia with its Bazhir tribes standing in for Bedouin. Carthak is Africa, conquered by an empire originally located only at the north end of the continent. Scanra is Scandinavia, while Galla is probably something like Germany, Tusaine is France, and Maren is Spain. The Copper Islands are Southeast Asia (specifically Malaysia, but broadly many of the different island cultures). The Yamani Isles are Japan, while Jindazhen to the west of Yaman is the Tortallverse's version of China. Sarain is something like Persia or Mongolia/Central Asia, with the nomadic K'mir standing in for the Mongols. The political troubles are reminiscent of interwarlord rivalries between Turkic and Mongol warlords in post-Mongol Empire Persia, Central Asia, and Mongolia.
Palladia and Merryland in Tranquilium seem like this for Tsarist Russia and Victorian Britain respectively, though the former is based on an archipelago and the latter is a republic; it's revealed pretty soon though that both were founded by people that crossed over from Earth over the years, mainly in the 19h century (and Merryland was mostly founded by Americans, at that!).
One of these for Ancient Rome is the setting for Tim Marquitz's War God novel, which is a Deconstructive Parody of this genre. The antiheroes intend to rig a tournament about this by upping the violence and murder to make their Fake Ultimate Hero look good so they can clean up when he crashes and burns.
in The Warded Man and sequels, the Krasian culture is medieval Arabia with a healthy dose of Sparta thrown in. The Thesan duchies are generic medieval European.
Robert Jordan's The Wheel of Time does this a lot, with a mix-and-match approach. Cairhien seems to be a mix of Ancien Regime France and Hieian Japan; Shienar is Sparta fused with Feudal Japan; Amadicia is modeled after Puritan America; the Seanchan are Ottoman Empire and Imperial China and Shogunate Japan, with Texan accents; Illian is a lot like Venice but its people have Greek-sounding names; Andor is similar to England and parts of the U.S.; the Aiel bear both Arabic and Native American similarities but look Irish and have Slavic accents; Tairens have much in common with Reconquista Spain crossed with Spanish-Colonial Era Philippines, the Sea Folk are reminiscent of Indians mixed with Polynesians; Shara appears to be a blending of Khanate Mongolia and Sub Saharan Africans and the list goes on.
In Who Fears Death, which takes place in an After the End Africa in which The Magic Comes Back, there is a war between the Okeke and the Nuru. The main character, Onyesonwu, is an Ewu, or a child of rape of an Okeke woman by a Nuru man. Even before the book is revealed to take place in Sudan, the Nuru are heavily implied to be Arab and the Okeke are implied to be black Africans. This is further confirmed in the prequelThe Book of Phoenix, in which "Arab" is considered a slur by the Nuru.
Nilfgaard seems to be some cross of Ancient Rome (expanding city-state, speaks language of scholars as native language, calls army units "legions"), The Soviet Union (heavy use of secret police) and the bad side of Germany (predilection for wearing black, sun-associated imagery, policies of ethnic and cultural purity, disdain for "degenerate" outsiders).
The Elves seem to be inspired by something, but the fandom is not sure whether it's the Celts conquered by Rome or Rome conquered by barbarians.
The various Northern Kingdoms are all representative of some European Medieval Kingdom. Redania is Poland, Kaedwin is Russia, Temeria is France, Cidaris and Verden are England, Aedirn is likely Bohemia or Switzerland, Lyria is similar to Spain, and the petty kingdoms in the far north like Kovir and Povis are representative of Italy.
In A Wizard of Earthsea, the Kargs have some striking similarities to Vikings, what with their habit of traveling around in longboats and doing the Rape, Pillage, and Burn routine on helpless villages. They're also the only people in Earthsea with light hair and pale skin. However when, in The Tombs of Atuan, we get a look at Kargish culture, it doesn't bear much resemblance to that of the Vikings.
The continent of Nova Terra is based on North America (even though two main nations are not!England and not!Byzantium). The Outwallers are analogous to American Indian tribes, furs and honey trade is important, and Fort Ticondaga is an expy of Fort Ticonderoga, down to its weakness.
Alba is medieval England, specifically shortly after the Black Plague, with the Wild attack standing in for the Plague and its results, such as better peasantry rights, smaller number of people and large uninhabited swaths of the country. They also have the hillmen, who are Scots counterparts.
Galle is medieval France, a prosperous state that nevertheless treats its peasantry like dirt and has knigths duelling to the death over the smallest things due to the country running on the Law of War.
Morea is late Byzantine Empire - slowly falling, increasingly reliant on foreign mercenaries, but with history dating back to the ancient empire.
Ifriqu'ya is Africa and the kaliphate states thereof, which are centres of science and Islamic faith.
Various background nations: Occitan and Arles are named after the medieval countries of the same name, and have similar culture; mercantile Hoek is Netherlands; Iberia is, obviously, Spain; the Archaics are Ancient Grome, mixing Greek philosophy with Roman law and military successes.
The shared universe of Leigh Bardugo's The Grisha Trilogy and Six of Crows features several. The most prominent is Ravka, based on Czarist Russia. There's also Shu Han, based on China, and Fjerda, based on the Nordic countries.
Dalmotti is Republic of Venice writ large, being a republic run by a Doge, with the capital called Veñaza City and the names sounding vaguely Italian.
The brief description of Svoden and their longships makes it seem very inspired by traditional portrayals of Viking-era Scandinavia.
The pirates of Saldonica bear resemblance to real-life Barbary pirates, including slave-taking, owning land and ports and hailing from a desert region.
Harry Potter's Goblins are pretty similar to Jews, and especially to their status in medieval European society; the often-mentioned Goblin Rebellions seem to indicate that they were not always submissive to the human Wizarding government, and they are an oppressed but proud people who, denied magic (which means they are denied all common jobs in wizarding society), have become merchants and bankers.