Alternate history or alternative history, sometimes abbreviated as AH, is a genre of fiction consisting of stories that are set in worlds in which one or more historical events unfolds differently from how they did in reality. It can be variously seen as a subgenre of literary fiction, science fiction, or historical fiction; different alternate history works may use tropes from any or all of these genres. Another term occasionally used for the genre is "allohistory" (literally "other history").Alternate History looks at "what if" scenarios from some of history's most pivotal turning points and presents a different version, sometimes based on science and fact, but often based on conjecture. Alternate history is the exploration of how the world would look today if various changes occurred and what these alternate worlds would be like forms the basis of this vast subject matter.Since the 1950s, this type of fiction has to a large extent merged with science fiction tropes involving time travel between alternate histories, psychic awareness of the existence of "our" universe by the people in another, or time travel that results in history splitting into two or more timelines. Cross-time, time-splitting, and alternate history themes have become so closely interwoven that it is impossible to discuss them fully apart from one another.In French, Italian, Spanish, Catalan and German, the genre of alternate history is called uchronie / ucronia / ucronía / Uchronie, which has given rise to the term Uchronia in English. This neologism is based on the prefix ου- (which in ancient Greek means "not/not any/no") and the ancient Greek χρόνος (chronos), meaning "time". A uchronia means literally "(in) no time". This term apparently also inspired the name of the alternate history book list, uchronia.net.In writing an alternate history, the author makes the conscious choice to change something in our past. According to Steven H Silver, alternate history requires three things: a point of divergence from the history of our world prior to the time at which the author is writing, a change that would alter history as it is known, and an examination of the ramifications of that change.Several genres of fiction have been confused as alternate histories. Science fiction set in what was the future but is now the past, like Arthur C. Clarke's 2001: A Space Odyssey or Nineteen Eighty-Four, are not alternate history because the author did not make the conscious choice to change the past. Secret history, works that document things that are not known to have happened historically but would not have changed history had they happened, is also not to be confused with alternate history.Alternate history is related to but distinct from counterfactual history—the term used by some professional historians when using thoroughly researched and carefully reasoned speculations on "what might have happened if…" as a tool of academic historical research.The earliest example of an alternate (or counterfactual) history is found in Livy's Ab Urbe condita (book IX, sections 17–19). Livy contemplated an alternative 4th century BC in which Alexander the Great expanded his empire westward instead of eastward; he asked, "What would have been the results for Rome if she had been engaged in war with Alexander?" Livy concluded that the Romans would likely have defeated Alexander.Joanot Martorell's 1490 epic romance Tirant lo Blanc, written when the loss of Constantinople to the Turks was still a recent and traumatic memory to Christian Europe, tells the story of the valiant knight Tirant The White from Brittany who gets to the embattled remnant of the Byzantine Empire, becomes a Megaduke and commander of its armies, and manages to fight off the invading Ottoman armies of Mehmet II, save the city from Islamic conquest, and even chase the Turks deeper into lands they had conquered before.In Book II Chapter 17 of Machiavelli's Discourses on Livy, he discusses what impact gunpowder artillery would have had on the Roman Empire had it been invented 1500 years earlier (and comes to the conclusion it would have made their conquests even greater as the primary advantage of artillery lies in attacking cities).One of the earliest works of alternate history published in large quantities for the reception of a popular audience may be the French Louis Geoffroy's Histoire de la Monarchie universelle: Napoléon et la conquête du monde (1812–1832) (History of the Universal Monarchy: Napoleon And The Conquest Of The World) (1836), which imagines Napoleon's First French Empire victorious in the French invasion of Russia in 1811 and in an invasion of England in 1814, later unifying the world under Bonaparte's rule.In the English language, the first known complete alternate history is Nathaniel Hawthorne's short story "P.'s Correspondence", published in 1845. It recounts the tale of a man who is considered "a madman" due to him perceiving a different 1845, a reality in which long-dead famous people are still alive such as the poets Burns, Byron, Shelley, and Keats, the actor Edmund Kean, the British politician George Canning, and even Napoleon Bonaparte.The first novel-length alternate history in English would seem to be Castello Holford's Aristopia (1895). While not as nationalistic as Louis Geoffroy's Napoléon et la conquête du monde, 1812–1823, Aristopia is another attempt to portray a utopian society. In Aristopia, the earliest settlers in Virginia discover a reef made of solid gold and are able to build a Utopian society in North America.A number of alternate history stories and novels appeared in the late 19th and early 20th centuries (see, for example, Charles Petrie's If: A Jacobite Fantasy ). In 1931, British historian Sir John Squire collected a series of essays from some of the leading historians of the period in the anthology If It Had Happened Otherwise. In this work, scholars from major universities as well as important non-university-based authors turned their attention to such questions as "If the Moors in Spain Had Won" and "If Louis XVI Had Had an Atom of Firmness". The essays range from serious scholarly efforts to Hendrik Willem van Loon's fanciful and satiric portrayal of an independent 20th century Dutch city state on the island of Manhattan. Among the authors included were Hilaire Belloc, André Maurois, and Winston Churchill.One of the entries in Squire's volume was Churchill's "If Lee Had Not Won the Battle of Gettysburg," written from the viewpoint of a historian in a world where the Confederacy had won the American Civil War, considering what would have happened if the North had been victorious (in other words, a character from an alternate world imagining a world more like the real one we live in, although not identical in every detail). This kind of speculative work, which posts from the point of view of an alternate history is variously known as a "recursive alternate history", a "double-blind what-if" or an "alternate-alternate history". Churchill's essay was one of the influences behind Ward Moore's alternate universe novel Bring the Jubilee, in which General Robert E. Lee won the Battle of Gettysburg, which paved the way for the eventual Confederacy victory in the American Civil War, renamed the "War of Southron Independence" in this timeline. The protagonist, autodidact Hodgins Backmaker, travels back to the aforementioned battle and inadvertently changes history, resulting in the emergence of our own timeline, and the consequent victory of the Union instead.American humorist author James Thurber parodied alternate history stories about the American Civil War in his 1930 story, "If Grant had been drinking at Appomattox", which he accompanied with this very brief introduction: "Scribner's magazine is publishing a series of three articles: 'If Booth Had Missed Lincoln', 'If Lee Had Won the Battle of Gettysburg', and 'If Napoleon Had Escaped to America'. This is the fourth."Another example of alternate history from this period (and arguably the first to explicitly posit cross-time travel from one universe to another as anything more than a visionary experience) is H.G. Wells' Men Like Gods (1923) in which several Englishmen are transferred via an accidental encounter with a cross-time machine into an alternate universe featuring a seemingly pacifistic and utopian Britain. When the Englishmen, led by a satiric figure based on Winston Churchill, try to seize power, the utopians simply point a ray gun at them and send them on to someone else's universe. Wells describes a multiverse of alternative worlds, complete with the paratime travel machines that would later become popular with U.S. pulp writers, but since his hero experiences only a single alternate world this story is not very different from conventional alternate history.The 1930s would see alternate history move into a new arena. The December 1933 issue of Astounding published by Nat Schachner's "Ancestral Voices," quickly followed by Murray Leinster's "Sidewise in Time". While earlier alternate histories examined reasonably straightforward divergences, Leinster attempted something completely different. In his "world gone mad", pieces of Earth traded places with their analogs from different timelines. The story follows Professor Minott and his students from a fictitious Robinson College as they wander through analogues of worlds that followed a different history.A somewhat similar approach was taken by Robert A. Heinlein in his 1941 novelette Elsewhen. A professor trains his mind to move his body across timelines. He then hypnotizes his students so they can explore more of them. Eventually each settles in the reality most suitable for him or her. Some of the worlds they visit are mundane, some very odd, and others follow science fiction or fantasy conventions.World War II produced alternate history for propaganda: both British and American authors wrote works depicting Nazi invasions of their respective countries as cautionary tales.The period around the second World War also saw the publication of the time travel novel Lest Darkness Fall by L. Sprague de Camp where an American academic travels to the Italy of the Ostrogoths at the time of the Byzantine invasion led by Belisarius. De Camp's work is concerned with the historical changes wrought by his time traveler, Martin Padway, thereby making the work an alternate history. Padway is depicted as making permanent changes and implicitly forming a new time branch.Time travel as the cause of a point of divergence (POD, creating two histories where before there was one, or simply replacing the future that existed before the time traveling event) has continued to be a popular theme. In Ward Moore's Bring the Jubilee, the protagonist lives in an alternate history in which the Confederate States of America won the Civil War, and he travels through time and brings about a Union victory in the Battle of Gettysburg.When a story's assumptions about the nature of time travel lead to the complete replacement of the visited time's future rather than just the creation of an additional time line, the device of a "time patrol" is often used, most notably in Poul Anderson's "Time Patrol" collection — where guardians race uptime and downtime to preserve the "correct" history. In the most celebrated of this series, Delenda Est, the interference of time-travelling outlaws causes Carthage to win the Second Punic War and destroy Rome with massive consequences for the present day.A more recent example is Making History by Stephen Fry, in which a time machine is used to alter history so that Adolf Hitler was never born — which ironically results in a more competent Nazi leader who has none of Hitler's faults or syphilis-induced mental illness, resulting in Nazi ascendancy and longevity in this altered timeline.H.G. Wells' "cross-time" or "many universes" variant (see above) was fully developed by Murray Leinster in his 1934 short story "Sidewise in Time" where sections of the Earth's surface begin changing places with their counterparts in alternate timelines.This subgenre was used early on for purposes far removed from quasi-academic examination of alternative outcomes to historical events. Fredric Brown employed it to satirize the science fiction pulps and their adolescent readers—and fears of foreign invasion—in the classic What Mad Universe (1949). In Clifford D. Simak's Ring Around the Sun (1953), the hero ends up in an alternate earth of thick forests in which humanity never developed but where a band of mutants is establishing a colony; the story line appears to frame the author's anxieties regarding McCarthyism and the Cold War.In the late 1940s and the 1950s, however, writers such as H. Beam Piper, Sam Merwin, Jr. and Andre Norton wrote thrillers set in a multiverse in which all alternate histories are co-existent and travel between them occurs via a technology involving portals and/or paratime capsules. These authors established the convention of a secret paratime trading empire that exploits and/or protects worlds lacking the paratime technology via a network of James Bond-style secret agents (Piper called them the "paratime police").This concept provided a convenient framing for packing a smorgasbord of historical alternatives (and even of timeline "branches") into a single novel, either via the hero chasing or being chased by the villain(s) through multiple worlds or (less artfully) via discussions between the paratime cops and their superiors (or between paratime agents and new recruits) regarding the histories of such worlds.The paratime theme is sometimes used without the police; Poul Anderson dreamed up the Old Phoenix tavern as a nexus between alternate histories. A character from a modern American alternate history Operation Chaos can thus appear in the English Civil War setting of A Midsummer's Tempest. In this context, the distinction between an alternate history and a parallel universe with some points in common but no common history may not be feasible, as the writer may not provide enough information to distinguish.Paratime thrillers published in recent decades often cite the many-worlds interpretation of quantum mechanics (first formulated by Hugh Everett III in 1957) to account for the differing worlds. Some science fiction writers interpret the splitting of worlds to depend on human decision-making and free will, while others rely on the butterfly effect from chaos theory to amplify random differences at the atomic or subatomic level into a macroscopic divergence at some specific point in history; either way, science fiction writers usually have all changes flow from a particular historical point of divergence (often abbreviated 'POD' by fans of the genre). Prior to Everett, science-fiction writers drew on higher dimensions and the speculations of P. D. Ouspensky to explain their characters' cross-time journeys.While many justifications for alternate histories involve a multiverse, the "many world" theory would naturally involve many worlds, in fact a continually exploding array of universes. In quantum theory, new worlds would proliferate with every quantum event, and even if the writer uses human decisions, every decision that could be made differently would result in a different timeline. A writer's fictional multiverse may, in fact, preclude some decisions as humanly impossible, as when, in Night Watch, Terry Pratchett depicts a character informing Vimes that while anything that can happen, has happened, nevertheless there is no history whatsoever in which Vimes has ever murdered his wife. When the writer explicitly maintains that all possible decisions are made in all possible ways, one possible conclusion is that the characters were neither brave, nor clever, nor skilled, but simply lucky enough to happen on the universe in which they did not choose the cowardly route, take the stupid action, fumble the crucial activity, etc.; few writers focus on this idea, although it has been explored in stories such as Larry Niven's story "All the Myriad Ways", where the reality of all possible universes leads to an epidemic of suicide and crime because people conclude their choices have no moral import.In any case, even if it is true that every possible outcome occurs in some world, it can still be argued that traits such as bravery and intelligence might still affect the relative frequency of worlds in which better or worse outcomes occurred (even if the total number of worlds with each type of outcome is infinite, it is still possible to assign a different measure to different infinite sets). The physicist David Deutsch, a strong advocate of the many-worlds interpretation of quantum mechanics, has argued along these lines, saying that "By making good choices, doing the right thing, we thicken the stack of universes in which versions of us live reasonable lives. When you succeed, all the copies of you who made the same decision succeed too. What you do for the better increases the portion of the multiverse where good things happen." This view is perhaps somewhat too abstract to be explored directly in science fiction stories, but a few writers have tried, such as Greg Egan in his short story The Infinite Assassin, where an agent is trying to contain reality-scrambling "whirlpools" that form around users of a certain drug, and the agent is constantly trying to maximize the consistency of behavior among his alternate selves, attempting to compensate for events and thoughts he experiences, he guesses are of low measure relative to those experienced by most of his other selves.Many writers—perhaps the majority—avoid the discussion entirely. In one novel of this type, H. Beam Piper's Lord Kalvan of Otherwhen, a Pennsylvania State Police officer, who knows how to make gunpowder, is transported from our world to an alternate universe where the recipe for gunpowder is a tightly held secret and saves a country that is about to be conquered by its neighbors. The paratime patrol members are warned against going into the timelines immediately surrounding it, where the country will be overrun, but the book never depicts the slaughter of the innocent thus entailed, remaining solely in the timeline where the country is saved.The cross-time theme was further developed in the 1960s by Keith Laumer in the first three volumes of his Imperium sequence, which would be completed in Zone Yellow (1990). Piper's politically more sophisticated variant was adopted and adapted by Michael Kurland and Jack Chalker in the 1980s; Chalker's G.O.D. Inc trilogy (1987–89), featuring paratime detectives Sam and Brandy Horowitz, marks the first attempt at merging the paratime thriller with the police procedural. Kurland's Perchance (1988), the first volume of the never-completed "Chronicles of Elsewhen", presents a multiverse of secretive cross-time societies that utilize a variety of means for cross-time travel, ranging from high-tech capsules to mutant powers. Harry Turtledove has launched the Crosstime Traffic series for teenagers featuring a variant of H. Beam Piper's paratime trading empire.The concept of a cross-time version of a world war, involving rival paratime empires, was developed in Fritz Leiber's Change War series, starting with the Hugo Award winning The Big Time (1958); followed by Richard C. Meredith's Timeliner trilogy in the 1970s, Michael McCollum's A Greater Infinity (1982) and John Barnes' Timeline Wars trilogy in the 1990s.Such "paratime" stories may include speculation that the laws of nature can vary from one universe to the next, providing a science fictional explanation—or veneer—for what is normally fantasy. Aaron Allston's Doc Sidhe and Sidhe Devil take place between our world, the "grim world" and an alternate "fair world" where the Sidhe retreated to. Although technology is clearly present in both worlds, and the "fair world" parallels our history, about fifty years out of step, there is functional magic in the fair world. Even with such explanation, the more explicitly the alternate world resembles a normal fantasy world, the more likely the story is to be labelled fantasy, as in Poul Anderson's "House Rule" and "Loser's Night." In both science fiction and fantasy, whether a given parallel universe is an alternate history may not be clear. The writer might allude to a POD only to explain the existence and make no use of the concept, or may present the universe without explanation to its existence.In 1962, Philip K. Dick published The Man in the High Castle, an alternate history in which Nazi Germany and Imperial Japan won World War II. This book contained an example of "alternate-alternate" history, in that one of its characters is the author of a book depicting a reality in which the Allies won the war, itself divergent from real-world history in several aspects.It was followed by Vladimir Nabokov's Ada or Ardor: A Family Chronicle (1969), a story of incest that takes place within an alternate North America settled in part by Czarist Russia, and that borrows from Dick's idea of "alternate-alternate" history (the world of Nabokov's hero is wracked by rumors of a "counter-earth" that apparently is ours). Some critics believe that the references to a counter-earth suggest that the world portrayed in Ada is a delusion in the mind of the hero (another favorite theme of Dick's novels). Strikingly, the characters in Ada seem to acknowledge their own world as the copy or negative version, calling it "Anti-Terra" while its mythical twin is the real "Terra." Not only history but science has followed a divergent path on Anti-Terra: it boasts all the same technology as our world, but all based on water instead of electricity, when a character in Ada makes a long-distance call, all the toilets in the house flush at once to provide hydraulic power.Isaac Asimov's short story What If– is about a couple who can explore alternate realities by means of a television-like device. This idea can also be found in Asimov's 1955 novel The End of Eternity. In that novel, the "Eternals" can change the realities of the world, without people being aware of it.Guido Morselli described the defeat of Italy (and subsequently France) in World War I in his 1975 novel Past Conditional (Contro-passato prossimo) where the static Alpine front line which divided Italy from Austria during that war collapses when the Germans and the Austrians forsake trench warfare and adopt blitzkrieg twenty years in advance.Kingsley Amis set his 1976 novel The Alteration in the 20th century, but major events in the Reformation did not take place, and Protestantism is limited to the breakaway Republic of New England. Martin Luther was reconciled to the Roman Catholic Church and later became Pope Germanian I.The Plot Against America (2004) by Philip Roth looks at an America where Franklin D. Roosevelt is defeated in 1940 in his bid for a third term as President of the United States, and Charles Lindbergh is elected, leading to increasing fascism and anti-Semitism in the U.S.Michael Chabon, occasionally an author of speculative fiction, contributed to the genre with his 2007 novel The Yiddish Policemen's Union. This book explores a world in which the State of Israel was destroyed in its infancy and many of the world's Jews instead live in a small strip of Alaska set aside by the US government for Jewish settlement. The story follows a Jewish detective solving a murder case in the Yiddish-speaking city of Sitka. Stylistically, Chabon borrows heavily from the noir and detective fiction genres, while exploring social issues related to Jewish history and culture. Apart from the alternate history of the Jews and Israel, Chabon also plays with other common tropes of AH Fiction; in the book, Germany actually loses the war even harder than in they did reality, getting hit with a nuclear bomb instead of just simply losing a ground war (subverting the common "what if Germany won WWII?" trope).The late 1980s and the 1990s saw a boom in popular-fiction versions of alternate history, fueled by the emergence of the prolific alternate history author Harry Turtledove, as well as the development of the steampunk genre and two series of anthologies—the What Might Have Been series edited by Gregory Benford and the Alternate … series edited by Mike Resnick. This period also saw alternate history works by S.M. Stirling, Kim Stanley Robinson, Harry Harrison, Howard Waldrop, and others.Since the late 1990s, Harry Turtledove has been the most prolific practitioner of alternate history and has been given the title "Master of Alternate History" by some. His books include those of Timeline 191 (a.k.a. Southern Victory), in which, while the Confederate States of America won the American Civil War, the Union and Imperial Germany defeat the Entente Powers in the two "Great War"s of the 1910s and 1940s (with a Nazi-esque Confederate government attempting to exterminate its Black population), and the Worldwar series, in which aliens invaded Earth during World War II. Other stories by Turtledove include A Different Flesh, in which America was not colonized from Asia during the last ice age; In the Presence of Mine Enemies, in which the Nazis won World War II; and Ruled Britannia, in which the Spanish Armada succeeded in conquering Britain in the Elizabethan era, with William Shakespeare being given the task of writing the play that will motivate the Britons to rise up against their Spanish conquerors. He also co-authored a book with actor Richard Dreyfuss The Two Georges, in which the United Kingdom retained the American colonies, with George Washington and King George III making peace. He did a two-volume series in which the Japanese not only bombed Pearl Harbor but also invaded and occupied the Hawaiian Islands.Perhaps the most incessantly explored theme in popular alternate history focuses on worlds in which the Nazis won World War Two. In some versions, the Nazis and/or Axis Powers conquer the entire world; in others, they conquer most of the world but a "Fortress America" exists under siege; while in others, there is a Nazi/Japanese Cold War comparable to the US/Soviet equivalent in 'our' timeline. Fatherland (1992) by Robert Harris, is set in Europe following the Nazi victory. Several writers have posited points of departure for such a world but then have injected time splitters from the future or paratime travel for instance James P. Hogan's The Proteus Operation. Norman Spinrad wrote The Iron Dream in 1972, which is intended to be a science fiction novel written by Adolf Hitler after fleeing from Europe to North America in the 1920s.In Jo Walton's "Small Change" series, the United Kingdom made peace with Hitler before the involvement of the United States in World War II, and fascism slowly strangled the UK. Former House Speaker Newt Gingrich and William R. Forstchen have written a novel, 1945, in which the U.S. defeated Japan but not Germany in World War II, resulting in a Cold War with Germany rather than the Soviet Union. Gingrich and Forstchen neglected to write the promised sequel; instead, they wrote a trilogy about the American Civil War, starting with Gettysburg: A Novel of the Civil War, in which the Confederates win a victory at the Battle of Gettysburg – however, after Lincoln responds by bringing Grant and his forces to the eastern theater, the Army of Northern Virginia is soon trapped and destroyed in Maryland, and the war ends within weeks. Also from that general era, Martin Cruz Smith, in his first novel, posited an independent American Indian nation following the defeat of Custer in The Indians Won (1970).Beginning with The Probability Broach in 1980, L. Neil Smith wrote several novels that postulated the disintegration of the U.S. Federal Government after Albert Gallatin joins the Whiskey Rebellion in 1794 and eventually leads to the creation of a libertarian utopia.A recent time traveling splitter variant involves entire communities being shifted elsewhere to become the unwitting creators of new time branches. These communities are transported from the present (or the near-future) to the past or to another time-line via a natural disaster, the action of technologically advanced aliens, or a human experiment gone wrong. S. M. Stirling wrote the Island in the Sea of Time trilogy, in which Nantucket Island and all its modern inhabitants are transported to Bronze Age times to become the world's first superpower. In Eric Flint's 1632 series, a small town in West Virginia is transported to 17th century central Europe and drastically changes the course of the Thirty Years' War, which was then underway. John Birmingham's Axis of Time trilogy deals with the culture shock when a United Nations naval task force from 2021 finds itself back in 1942 helping the Allies against the Empire of Japan and the Germans (and doing almost as much harm as good in spite of its advanced weapons). Similarly, Robert Charles Wilson's Mysterium depicts a failed U.S. government experiment which transports a small American town into an alternative version of the U.S. run by believers in a form of Christianity known as Gnosticism, who are engaged in a bitter war with the "Spanish" in Mexico (the chief scientist at the laboratory where the experiment occurred is described as a Gnostic, and references to Christian Gnosticism appear repeatedly in the book).Many fantasies and science fantasies are set in a world that has a history somewhat similar to our own world, but with magic added. Some posit points of divergence, but some also feature magic altering history all along. One example of a universe that is in part historically recognizable but also obeys different physical laws is Poul Anderson's Three Hearts and Three Lions in which the Matter of France is history, and the fairy folk are real and powerful. A partly familiar European history for which the author provides a point of divergence is Randall Garrett's "Lord Darcy" series: a monk systemizing magic rather than science, so the use of foxglove to treat heart disease is called superstition. The other great point of divergence in this timeline occurs in 1199, when Richard the Lionheart survives the Siege of Chaluz and returns to England, making the Angevin Empire so strong it survives into the 20th century.Jonathan Strange & Mr Norrell takes place in an alternative version of England where a separate Kingdom ruled by the Raven King and founded on magic existed in Northumbria for over 300 years. In Patricia Wrede's Regency fantasies, Great Britain has a Royal Society of Wizards, and in Poul Anderson's A Midsummer Tempest William Shakespeare is remembered as the Great Historian, with the novel itself taking place in the era of Oliver Cromwell and Charles I, with an alternate outcome for the English Civil War and an earlier Industrial Revolution.The Tales of Alvin Maker series by Orson Scott Card (a parallel to the life of Joseph Smith, founder of the Latter Day Saint movement) takes place in an alternate America, beginning in the early 19th century. Prior to that time, a POD occurred: England, under the control of Oliver Cromwell, had banished "makers", or anyone else demonstrating "knacks" (an ability to perform seemingly supernatural feats) to the North American continent. Thus the early American colonists embraced as perfectly ordinary these gifts, and counted on them as a part of their daily lives. The political division of the continent is considerably altered, with two large English colonies bookending a smaller "American" nation, one aligned with England, and the other governed by exiled Cavaliers. Actual historical figures are seen in a much different light: Ben Franklin is revered as the continent's finest "maker", George Washington was executed at the hands of an English army, and "Tom" Jefferson is the first president of "Appalachia", the result of a compromise between the Continentals and the British.On the other hand, when the "Old Ones" still manifest themselves in England in Keith Roberts's Pavane, which takes place in a technologically backward world after a Spanish assassination of Elizabeth I allowed the Spanish Armada to conquer England, the possibility that the fairies were real but retreated from modern advances makes the POD possible: the fairies really were present all along, in a secret history. Again, in the English Renaissance fantasy Armor of Light by Melissa Scott and Lisa A. Barnett, the magic used in the book, by Dr. John Dee and others, actually was practiced in the Renaissance; positing a secret history of effective magic makes this an alternate history with a POD, Sir Philip Sidney's surviving the Battle of Zutphen, and shortly thereafter saving the life of Christopher Marlowe.Many works of fantasy posit a world in which known practitioners of magic were able to make it function, and where the consequences of such reality would not, in fact, disturb history to such an extent as to make it plainly alternate history. Many ambiguous alternate/secret histories are set in Renaissance or pre-Renaissance times, and may explicitly include a "retreat" from the world, which would explain the current absence of such phenomena.When the magical version of our world's history is set in contemporary times, the distinction becomes clear between alternate history on the one hand and contemporary fantasy, using in effect a form of secret history (as when Josepha Sherman's Son of Darkness has an elf living in New York City, in disguise) on the other. In works such as Robert A. Heinlein's Magic, Incorporated where a construction company can use magic to rig up stands at a sporting event and Poul Anderson's Operation Chaos and its sequel Operation Luna, where djinns are serious weapons of war—with atomic bombs—the use of magic throughout the United States and other modern countries makes it clear that this is not secret history—although references in Operation Chaos to degaussing the effects of cold iron make it possible that it is the result of a POD. The sequel clarifies this as the result of a collaboration of Einstein and Planck in 1901, resulting in the theory of "rhea tics". Henry Moseley applies this theory to "degauss the effects of cold iron and release the goetic forces." This results in the suppression of ferromagnetism and the re-emergence of magic and magical creatures.Alternate history shades off into other fantasy subgenres when the use of actual, though altered, history and geography decreases, although a culture may still be clearly the original source; Barry Hughart's Bridge of Birds and its sequels take place in a fantasy world, albeit one clearly based on China, and with allusions to actual Chinese history, such as the Empress Wu. Richard Garfinkle's Celestial Matters incorporates ancient Chinese physics and Greek Aristotelian physics, using them as if factual.A fantasy version of the paratime police was developed by children's writer Diana Wynne Jones in her Chrestomanci quartet (1977–1988), with wizards taking the place of high tech secret agents. Among the novels in this series, Witch Week stands out for its vivid depiction of a history alternate to that of Chrestomanci's own world rather than our own (and yet with a specific POD that turned it away from the "normal" history of most worlds visited by the wizard).Terry Pratchett's works include several references to alternate histories of Discworld. Men At Arms observes that in millions of universes, Edward d'Eath became an obsessive recluse rather than the instigator of the plot that he is in the novel. In Jingo, Vimes accidentally picks up a pocket organizer that should have gone down another leg of the Trousers of Time, and so can hear the organizer reporting on the deaths that would have occurred had his decision gone otherwise. Indeed, Discworld contains an equivalent of the Time Patrol in its History Monks. Night Watch revolves around a repair of history after a time traveller’s murder of an important figure in Vimes's past. Thief of Time presents them functioning as a full-scale Time Patrol, ensuring that history occurs at all.Alternate history has long been a staple of Japanese speculative fiction with such authors as Futaro Yamada, Ryo Hanmura writing novels set in recognizable historical settings with supernatural or science fiction elements present. In 1973, Ryo Hanmura wrote Musubi no Yama Hiroku which recreated 400 years of Japan's history from the perspective of a secret magical family with psychic abilities. The novel has since come to be recognized as a masterpiece of Japanese speculative fiction. Twelve years later, author Hiroshi Aramata wrote the groundbreaking Teito Monogatari which reimagined the history of Tokyo across the twentieth century in a world heavily influenced by the supernatural.The TV show Sliders explores different possible alternate realities by having the protagonist "slide" into different parallel dimensions of the same planet earth.For the same reasons that this genre is explored by role-playing games, alternate history is also an intriguing backdrop for the storylines of many video games. A famous example of an alternate history game is Command & Conquer: Red Alert. Released in 1996, the game presents a point of divergence in 1946 where Albert Einstein goes back in time to prevent World War II from ever taking place by erasing Adolf Hitler from time after he is released from Landsberg Prison in 1924. He is successful in his mission, but in the process allows Joseph Stalin and the Soviet Union to become powerful enough to launch a massive campaign to conquer Europe.In the Civilization Series, the player guides a civilization from prehistory to the present day, creating radically altered versions of history on a long time-scale. Several scenarios recreate a particular period which becomes the "point of divergence" in an alternate history shaped by the player's actions. Popular examples in Sid Meier's Civilization IV include Desert War, set in the Mediterranean theatre of World War II and featuring scripted events tied to possible outcomes of battles; Broken Star, set in a hypothetical Russian civil war in 2010; and Rhye's and Fall of Civilization, an 'Earth simulator' designed to mirror a history as closely as possible but incorporating unpredictable elements to provide realistic alternate settings.In some games such as the Metal Gear and Resident Evil series, events that were originally intended to represent the near future at the time the games were originally released later ended up becoming alternative histories in later entries in those franchises. For example, Metal Gear 2: Solid Snake (1990), set in 1999, depicted a near future that ended up becoming an alternative history in Metal Gear Solid (1998). Likewise, Resident Evil (1996) and Resident Evil 2 (1998), both set in 1998, depicted near-future events that had later become an alternative history by the time Resident Evil 4 (2005) was released.In the 2009 steampunk shooter, Damnation is set on an alternate version of planet Earth, in the early part of the 20th century after the American Civil War, which had spanned over several decades, where steam engines replace combustion engines. The game sees the protagonists fighting off a rich industrialist who wants to do away with both the Union and Confederacy in one swift movement and turn the United States of America into a country called the "American Empire" with a totalitarian dictatorship.Crimson Skies is one example of an alternate history spawning multiple interpretations in multiple genres. The stories and games in Crimson Skies take place in an alternate 1930s United States, where the nation crumbled into many hostile states following the effects of the Great Depression, the Great War, and Prohibition. With the road and railway system destroyed, commerce took to the skies, which led to the emergence of air pirate gangs who plunder the aerial commerce.The game Freedom Fighters portrays a situation similar to that of the movie Red Dawn and Red Alert 2, though less comically than the latter. The point of divergence is during World War II, where the Soviet Union develops an atomic bomb first and uses it on Berlin. With the balance of power and influence tipped in Russia's favor, history diverges; brief summaries at the beginning of the game inform the player of the Communist bloc's complete takeover of Europe by 1953, a different ending to the Cuban Missile Crisis, and the spread of Soviet influence into South America and Mexico.Similarly, the 2007 video game World in Conflict is set in 1989, with the Soviet Union on the verge of collapse. The point of divergence is several months before the opening of the game, when Warsaw Pact forces staged a desperate invasion of Western Europe. As the game begins, a Soviet invasion force lands in Seattle, taking advantage of the fact that most of the US military is in Europe.The game Battlestations: Pacific, released in 2008, offered in alternate history campaign for the Imperial Japanese Navy, wherein Japan destroys all three carriers in the Battle of Midway, which follows with a successful invasion of the island. Because of this, the United States lacked any sort of aerial power to fight the Japanese, and is continuously forced into the defense.Turning Point: Fall of Liberty, released in February 2008, is an alternate history first person shooter where Winston Churchill died in 1931 from being hit by a taxi cab. Because of this, Great Britain lacks the charismatic leader needed to keep the country together and Nazi Germany successfully conquers Great Britain via Operation Sealion in 1940. Germany later conquers the rest of Europe, North Africa and the Middle East while mass-producing their wunderwaffe. The Axis launch a surprise invasion of an isolationist United States' Eastern Seaboard in 1953, which forces the country to surrender and submit to a puppet government.Another alternate history game involving Nazis is War Front: Turning Point in which Adolf Hitler died during the early days of World War II and thus, a much more effective leadership rose to power. Under the command of a new Fuehrer (who is referred to as "Chancellor", and his real name is never revealed), Operation Sealion succeeds and the Nazis successfully conquer Britain, sparking a cold war between the Allied Powers and Germany.The Fallout series of computer role-playing games is set in a divergent America, where history after World War II diverges from the real world to follow a retro-futuristic timeline. For example, fusion power was invented quite soon after the end of the war, but the transistor was either delayed or never was developed. The result was a future that has a 1950s 'World of Tomorrow' feel to it, with extremely high technology such as artificial intelligence implemented with thermionic valves and other technologies now considered obsolete.Many game series by Swedish developer Paradox Interactive start off at a concise point in history, allowing the player to immerse in the role of a contemporary leader and alter the course of in-game history. The most prominent game with this setting is Crusader Kings II.S.T.A.L.K.E.R. games have an alternative history at Chernobyl Exclusion Zone, where a special area called "The Zone" is formed.Wolfenstein: The New Order is set in an alternate 1960 in which the Nazis won the Second World War, also thanks to their acquisition of high technology.Fans of alternate history have made use of the internet from a very early point to showcase their own works and provide useful tools for those fans searching for anything alternate history, first in mailing lists and usenet groups, later in web databases and forums.The "Usenet Alternate History List" was first posted on April 11, 1991, to the Usenet newsgroup rec.arts.sf-lovers. In May 1995, the dedicated newsgroup soc.history.what-if was created for showcasing and discussing alternate histories. Its prominence declined with the general migration from unmoderated usenet to moderated web forums, most prominently AlternateHistory.com, today the self-described "largest gathering of alternate history fans on the internet".In addition to these discussion forums, in 1997 Uchronia: The Alternate History List was created as an online repository, now containing over 2,900 alternate history novels, stories, essays, and other printed materials in several different languages. Uchronia was selected as the Sci Fi Channel's "Sci Fi Site of the Week" twice.Collaborative attempts by several amateur writers have led to notable accomplishments. The contributors at Ill Bethisad have made two constructed languages: Brithenig and Wenedyk.