Darkness Series

A cycle of six Doorstopper books by Harry Turtledove which covers the story of World War II from a global perspective, using Loads And Loads Of Viewpoint Characters from all the major participant nations (and Finland). The twist is that this is not the World War II we know, but the same sequence of events transposed onto a generic Low Fantasy world which has used Functional Magic to achieve industrialisation. Fantastic equivalents for real weapons and technologies abound: dragons for aircraft, leviathans for submarines, behemoths for tanks...

One of the more interesting twists is that the Fantasy Counterpart Cultures do not match up with the countries they're representing: Turtledove randomly mixed ethnicities and used languages and place names from more obscure countries. For example, the nation of Kuusamo is the equivalent of the United States, but is inhabited by Finnish-speaking East Asians. This allows the reader to take a slightly more objective view of the conflict.

In addition to this, most of the continents are in the southern hemisphere of this planet, east and west are flipped but north and south are not. This means countries which are cold in Real Life are often hot in the Darkness world and vice versa: for example, Zuwayza (Fantastic Finland) is a red hot desert country while the Land of the Ice People (Fantastic North Africa) is an icebound wasteland.

This book series contains examples of:

 * Alternate History: Sort of, appropriately enough given Turtledove's other works. Putting things in Real Life terms, this version of World War II starts when Germany marches into Danzig--Poland is not conquered until the end of the first book. Britain isn't a member of the Allies from the start. And America and Japan are already at war before the main war begins.
 * America Wins the War: Largely averted; Kuusamo plays the same major role as the United States in Real Life, but it's made clear that it's the Unkerlanters (Fantastic Soviets) who do most of the fighting.
 * Anyone Can Die: Plenty of viewpoint characters die after featuring in multiple books. They are often replaced by one of their friends or comrades who we've already met in their narrative to ease the transition. (Turtledove also uses this trick in some of his other series).
 * Broad Strokes: This is a fantastic version of World War II, but not everything exactly matches up, the order of events is sometimes different, and expectations are played with.
 * Brother Sister Incest: Not an actual example, but invoked: Kaunian Vanai creates a spell which allows her to take on a Forthwegian appearance, in order to hide from the Algarvians. Her Forthwegian lover Ealstan is a bit Squicked that the spell for some reason makes her look almost exactly like his sister Conberge.
 * The Caligula: King Swemmel (Fantastic Josef Stalin), who boils his enemies in huge kettles. Oddly enough, King Mezentio (Fantastic Adolf Hitler) comes across as less crazy (but strong-willed), although he's rarely seen.
 * Crazy Cultural Comparison: Turtledove likes this trope; there are constant cultural comparisons between the various racial groups and countries -- some fairly unpleasant. The one that sticks out is the fact that the people of baking hot Zuwayza commonly go naked except for a wide-brimmed hat and sandals. Most foreigners consider this bizarre, but the ambassador from Algarve goes native - though he still gets funny glances from the Zuwayzi as Algarvians are all circumcised.
 * Dragon Rider: Deconstructed -- while dragons are commonly used for aerial combat, they are nasty, foul-tempered, violent, and stupid creatures who have to be cruelly treated from birth in order to discourage them from killing their riders.
 * Fantastic Nuke: Pekka's storyline is about the magical equivalent of the Manhattan Project. The Fantastic Nuke is finally used at the end of the last book,.
 * Fantasy Counterpart Culture: The Darkness series does this rather directly, but subverts it somewhat by mixing and matching cultures around -- for example, the equivalent of Nazi Germany has Celtic ethnicity and Italian language.
 * Also done for the purpose of irony as the fantastic equivalent of Jews are described as being fair and blond (the Nazis' espoused "Aryan ideal") and implied to be the remnants of the equivalent of the Roman Empire (which Nazi Germany took many motiffs from).
 * Foregone Conclusion: Once you've figured out who's who, you know who's going to lose--although not everything is exactly like our World War II.
 * Functional Magic: Rule Magic (spells are weakened by proximity to water, while they are powered up when close to "ley lines") and Device Magic ("sticks" and "eggs", magical equivalents of guns and bombs, respectively), as well as some forms of Alchemy. The Nazi-analogue Algarvians also make use of a kind of Black Magic toward the end of the war, as a last resort; it's powered by mass human sacrifice, drawing upon the many ethnic prisoners they took over the course of the conflict. There's also a magical Manhattan Project, utilising heavily mathematical and rigorous investigation of the fundamental laws of magic, much akin to the study of physics.
 * Human Resources / Powered By a Forsaken Child: The Algarvians' Holocaust-powered superweapon, which uses mass human sacrifice in what is implied to be a Deal With the Devil, or rather the Powers Below.
 * The Laws of Magic: At least two of them, including the Law Of Contagion.
 * Magic a Is Magic A: Like all Turtledove's fantasy settings, this one runs on two basic rules of magic--the "Law of Similarity" (two visually similar things are magically connected) and the "Law of Contagion" (two things that have touched are magically connected). Research magicians find a new universal principle connecting the two laws, which allows them to make a Fantastic Nuke.
 * Oh My Gods: Most countries' people seem to follow roughly the same dualistic religion, and swear by "Powers above!" and "Powers below!" The Gyongyosians, being the odd one out, instead worship the stars, and swear by them. The Ice People are the only ones whose religion actually mentions 'gods' and they are considered backwards and primitive by everyone else.
 * Our Dragons Are Different: They're considered rather stupid creatures that 'pilots' have to beat with crops to get them to cooperate.
 * People of Hair Colour: Used extensively; hair colour, along with clothing (kilts vs trousers vs tunics) is the main racial identifier. Algarvic (Fantastic Germanic) peoples like the Algarvians, Sibians and Lagoans (Fantastic Germans, Danes/Norwegians and British) have red hair. Kaunian (Romance and Jewish) peoples like the Jelgavans, Valmierans and the Kaunians of Forthweg (Low Countries, French and Jews of Poland) have blond hair. The 'Slavic' peoples of Unkerlant, Forthweg and Grelz (Russia, Poland and Ukraine) have brown hair.
 * The Plot Reaper: When Pekka and Fernao, both major characters from the beginning, finally meet at the series' halfway point, they slowly start to fall in love with each other; Pekka is married, but both she and her husband Leino are being kept in total isolation with their colleagues working on separate top secret projects. Meanwhile, Leino's shagging one of his coworkers (who aside from her looks really has nothing going for her) with far fewer reservations. This could have created a very complicated and messy situation when everyone met, but instead Turtledove kills Leino and his lover at the beginning of the last book. Somewhat played with as news of Leino's death (but not his affair, no one ever finds out about that) initially makes Pekka feel enormously guilty and break off her relationship with Fernao, though eventually they get back together and get married.
 * Wearing a Flag On Your Head: Dragons and other war creatures are painted in the colours of the countries' flags or military uniforms: for example, Algarve uses red, white and green, Kuusamo uses sky-blue and sea-green, and Unkerlant uses rock-grey.
 * Your Normal Is Our Taboo: The Gyongyosians (Fantastic Japanese) have a taboo about eating goat meat. The Zuwayzans (Fantastic Finns) wear little to no clothing due to the heat of their country. Individual members of the Ice People (Fantastic North Africans) have particular fetish animals whose meat they will not eat. Algarvians are all circumcised at the age of fourteen, which the other nations find to be a strange practice.