Recently some people have attempted to give this to Countess Elizabeth Báthory, one of the worst serial killers in history. Nicknamed the 'Blood Countess,' she is believed to be responsible for torturing hundreds of young women to death, but they only had the evidence to convict her for 80 of them. First with her husband and, after he died, as a solo killer with three friends acting as accomplices, she would order them into her dungeon and sadistically beat them. Despite having hundreds of witnesses testify that young women would regularly enter the castle and only their corpses would come out, some people still claim she was innocent and the victim of a conspiracy by the Catholic church and the Hapsburg empire that ruled Hungary at the time, claiming that they wanted her money and land, and did not like seeing a woman in power. There are a few problems with these theories: first, her crimes were reported by the Lutheran church (which she was a member of), secondly, the Hapsburg waited about a decade between the crimes being first reported and launching an investigation, and finally, she did not have any land, money, or direct power after her husband died: their son inherited his father’s land, and their eldest daughter acted as regent while he was a minor. While it is true that, as the wife, and later, mother of the Count, she had a lot of pull, she was technically powerless. About the only detail about her life that actually is certainly a myth are the rumours that she would bathe in the blood of her many victims. On a related note, Báthory has the strange distinction of also receiving Historical Villain Upgrades at the same time, as other works change her from the particularly depraved human being she was in real life to a vampire. Two sympathetic portrayals from recent movies are:
Bathory took the position that she was completely innocent of any of the murders, and was really a kind and loving mother and ruler who was in the wrong place at the wrong time, and was the victim of the malicious slanders of greedy noblemen. That's not even getting into the ridiculousness of the monks spying on her.
The Countess is similar, but with one main difference: Elizabeth Bathory is guilty of several murders. However, she is driven to it by circumstances, and an attempt to stay young and beautiful while she is in power. In this film, she is definitely a Woobie, Destroyer of Worlds. You still feel sorry for her and sympathize with what she is going through
Wyatt Earp, in portrayals such as My Darling Clementine (1946) and The Life and Legend of Wyatt Earp (1955), is portrayed as the paragon of the Western lawman. Even more modern takes like Tombstone still can't uncouple themselves entirely from this image. In reality, he was much shadier and more self-interested. Earp himself was good at branding himself. The historical record seems to present the Earps and the various families like the Clantons or the McLaurys as no better than each other - more feuding families than cops vs. robbers. On the other hand, most of the supposed Wild West tends to get treated like that. Earp's legend was also partially built on the fact he served as an "advisor" on a number of early Western movies.
King Richard I of England has entered mythology as Richard the Lionheart, paragon of knighthood, King Arthur come again. The real Richard was a deeply complex individual, warlike, greedy (according to one story, Richard claimed he would sell London to finance his wars if he could find a buyer), probably not actually an Anglophone, and not above stabbing someone in the back; this becomes a case of Values Dissonance. He did have a good sense of humor, being one of the few medieval kings of whom amusing quips are recorded. Not a cardboard villain, but not the cardboard angel of Ivanhoe and the The Adventures of Robin Hood.
Vlad "the Impaler" was a particularly ruthless warlord who usually gets a Historical Villain Upgrade due to his association with Bram Stoker's novel Dracula. However, he is also a celebrated national hero in Romania, since most of that ruthlessness was at the expense of their enemy, the Turks.
While in The Divine Comedy, Dante puts him as a great traitor in the deepest level of hell, William Shakespeare saw him as a man who died for the Republic's interests. For a long time the prevailing opinion among liberal-minded intellectuals that Brutus was a shining paragon of republicanism and Caesar a grasping tyrant. They probably patterned this off of his ancestor Lucius Brutus, slayer of the last king of Rome, who (if he actually existed) got a Historical Hero Upgrade in Roman historiography itself.
That is an interpretation of what Shakespeare wrote. Given his lack of otherwise republican sympathies, it is possible that Shakespeare did not regard Caesar's accepting a crown as wicked, given he was not a usurper, and that he had Caesar's ghost haunt Brutus because it had been wrong to kill him.
Plutarch wrote in his book of historical biographies, Parallel Lives, that Brutus was the last great republican, so it isn't unambiguously a case of an upgrade.
Works about the French Revolution will often tend to cast Georges Danton as a moderate liberal revolutionary killed by the revolutionary excesses of the Reign of Terror. Not quite true. Danton was less enthusiastic about the Terror than many of the Jacobins, but unlike them he commanded huge respect and loyalty from the militant Parisian crowd, which was often even more extreme than the Jacobins.
Jeanne d'Arc, of course, does this to Joan of Arc. Another, more peculiar example lies in Giles de Rais, who was an infamous serial killer in real life, but here he is one of Joan's most steadfast allies. By all accounts he WAS a loyal French royalist AND a savage, possibly, Satanic murderer. The two aren't incompatible. That, and there is no small amount of dispute over WHEN his murders started.
Mark Twain's Personal Recollections of Joan of Arc, by the Sieur Louis de Conte, which Twain called his favorite of all his books, is a rare example of near-total Sarcasm Failure on Twain's part, being a straight, starry-eyed depiction of a Lady of War and her noble death at the hands of evil. A lot of people called him out on this, including George Bernard Shaw, who kept Joan the traditional heroine in his play Saint Joan, but felt that her enemies had been the victims of a Historical Villain Upgrade and opted for White and Grey Morality in his version of events. Quite incorrectly, however, as regards Peter Cauchon, Bishop of Beauvais, who was a swine.
Pretty much inverted by the musical Elisabeth, which presents her as so damaged and unstable that she spends her entire adult life hallucinating that Death (in the form of a beautiful young man) is trying to seduce her.
He didn't set out to prove the world was not flat, - everyone who was educated at the time knew that the world was round - he set out to find an easy route to Asia by going West, to avoid having to go around Africa (which was controlled by Portugal at the time). What made his voyage so outrageously unacceptable was that he assumed the world was only six thousand miles in circumference, which was far below most estimations at the time and under a quarter of the actual figure. Had there not been a huge continent barring his way, he and his crew would have likely starved to death. Some versions have him suspecting that there's another continent there and for whatever reason not letting on.
He even found someone to calculate the earth's circumference for him. And when that person told him, he got the unit of measure wrong...
One of Columbus' problems is that he was relying on a map of the world by the Florentine polymath Paolo del Pozzo Toscanelli, who got the circumference of the Earth closer to right but who got the size of Asia wrong—by thousands of miles. This was in part because he was relying on the reports of the very few Europeans who had actually been east of the Levant; the map he made was remarkably accurate in Europe and North Africa, but eastward everything was stretched.
His systematic enslavement of the Taino Indians, his introduction of Old World diseases (especially smallpox) to the New World and his discovery, contraction and bringing back of Syphilis is almost never mentioned.
Not that he had any way to know about the last, and certainly didn't do it deliberately.
Hard to "discover" a New World that was already inhabited yes? Columbus also was technically not the first European either, preceded centuries ago by Leif Ericson. Though given that the Norse Vinland colonies all failed, Columbus is still more historically significant.
Much of Columbus' Historical Hero Upgrade can be attributed to the early United States in general and Washington Irving in particular, who sought to distance America from Great Britain by highlighting/exaggerating the accomplishments of a non-British explorer.
Matthias Corvinus ruled Hungary with an iron fist. He was known for imprisoning the nobles who crowned him king, and instituting high taxes to maintain his army of Elite Mooks. Despite this, he is known as Hungary's greatest and most iconic folk hero, for his sense of justice and his rumoured habit of mingling with the common folk. The fact that the kingdom of Hungary was living it's golden age during his rule, and practically died with him, also helps his case.
Which however wasn't really an unfair description given the massacres committed against civilians and unarmed soldiers with the assistance of Jesse and Frank James by the "bushwhacker" units lead by William Clark Quantrill and "Bloody Bill" Anderson.
This seems to have been ended permanently with The Assassination Of Jesse James which, while still making him very sympathetic, also shows how sadistic, brutal and unstable he really was, even to his close friends. The opening claims he committed at least seventeen murders and felt no remorse.
Clyde Barrow and Bonnie Parker have been romanticized as dashing outlaw lovebirds to the point that it's easy to forget that their "flaunting of society's rules" left a lot of dead bodies in its wake, both police and civilian. As a rule, criminals generally don't get four machine guns emptied into their bodies for being Lovable Rogues who just rob banks for fun.
The Knights Templar in general and Jacques de Molay, their last Grand Master, in particular. Thanks to The Accursed Kings of Maurice Druon for adding to this. Let's just say Philip IV had more than one good reason to wipe them out, and at the time this was approved at least as much as decried. Jacques personally contributed both to hostility from the King of France and to making his order look more like a liability than an asset.
Russian bard "Chancellor Gi" wrote a mocking song The plea of Jacques de Molay about said dead Templar worrying now he's going to be canonized, and remembering details such as his bastards and shifty way of his ascension to the chair.
While 19th Century Abolitionists were not racist for their time, many modern audiences assume that they held 21st Century conventional views on race. In fact, most of them believed blacks to be inferior to whites, but also thought it wrong to enslave them anyway. The vast majority of them would be considered very very racist in this day and age.
Due to many biographies written about American presidents, along with multiple varying portrayals in the media and the concept of American exceptionalism, this trope is pretty much inevitable and very common with many of the more well-liked presidents in American history; some examples include:
George Washington is usually portrayed as a freedom fighter and a pillar of moral character who established that the president will step down in a peaceful transition of power after a brief rule. This view glosses over his ownership of slaves, his controversial tactical decisions during the Revolutionary War, his brutal and highly successful campaigns against the Native Americans while leading a portion of the Virginia Regiment, an embarrassing friendly fire incident during the Forbes Expedition to take Fort Duquesne, and the little fact that he kinda sorta ignited the French and Indian War (the American theater of the Seven Years' War) by ambushing a French patrol, leading to the Battle of Jumoville Glen. Whoops. Is it any wonder John Adams referred to him as "Old Muttonhead"?
Andrew Jackson is seen in portrayals as a war hero and a populist Bad Ass who loved his wife dearly and stood up for the people against the wealthy elite. However this overlooks his responsibility for the Trail of Tears and Indian Removal that forced many Native Americans from their lands and caused many to die in the process. (Through to be fair, he did it because he believed it would prevent war with the tribes and, possibly, a civil war.).
Theodore Roosevelt is often seen as a model of badassery and the founder of modern progressiveism. While this may be true, it overlooks his imperialistic tendencies in Cuba and the Philippines during the US wars there from the 1890s to the 1900s, as well as his support for US entry in World War I.
Woodrow Wilson is often seen as a model of Progressivism and idealism, when in fact he appointed the heads of large corporations to agencies supposedly regulating business, instated the policy of mandatory segregation, was one of the first of the Red Scare anti-communist and anti-socialist presidents, and did little for labor, women, and other groups in need of assistance. This seemed to have shifted in recent years, where he is looked on much more critically nowadays for exactly these reasons. With many actually calling him one of the worst presidents in the US in the early 20th century, especially on AlternateHistory.com.
Henry A. Wallace, Franklin D. Roosevelt's second vice president is often seen as an idealist who would have not nuked Japan and could have brought everlasting peace between the US and the Soviet Union following the end of the Cold War had he became president instead of Harry Truman. Through whether he would be a good president or not is up for debate, and he might have not dropped the bomb on Japan, this viewpoint tends to overlook responsibilities on both sides that started the Cold War by solely focusing on the US responsibility in starting the Cold War. Furthermore, they tend to overlook the fact that he knew nothing about Stalin's crimes, and quickly became anticommunist after he received knowledge about them, supporting Eisenhower and Nixon in the 1952 and 1960 elections respectively. An example where this is seen is the Untold History of the United States by Oliver Stone, which gives both Franklin D. Roosevelt and Henry Wallace, along with John F. Kennedy Historical Hero Upgrades (through it calls out FDR's possible complicity in the appeasement process), while giving Harry Truman a Historical Villain Upgrade, placing the blame on the cold war solely on him and anti-Communist circles in the US. To what extent this was justified is a very controversial topic, and still a major topic of debate in the present day. At the same time, there are those who think he was a Communist sell-out trying to betray America to the Soviets due to the Communists supporting his 1948 third party run, so it goes both ways.
Dwight D. Eisenhower is often portrayed as an admirable and badass general in WWII and a great president who maintained stability in the early years of the cold war, and warned of the Military-Industrial complex. While he could be seen as admirable and these portrayals deserve credit, they tend to overlook some of his shady foreign policy actions that he has done as president, such as his support of the coups against democratically elected governments such as Prime Minister Mossadegh in Iran and President Arbenz in Guatemala, the former which critically strained relations between the Islamic world and the West to this day, and the latter which placed Guatemala under the successive rule of military dictatorships for decades, along with his support of the Batista regime in Cuba. He also blocked an important vote on Vietnamese unification and installed pro-US dictator Ngo Dinh Diem in South Vietnam after finding out that 80% of the Vietnamese would have sided with Ho and the Communists in said referendum, setting the stage for US involvement in the Vietnam War.
John F. Kennedy is often seen as the "last true president" of the United States and is seen in many circles as a president who saved the world from Armageddon and would have avoided Vietnam and saved America from <insert Villainous secret society here that killed him in Conspiracy Theories> had he lived. He is almost canonized (along with Andrew Jackson sometimes) in Conspiracy Theorist circles as a pillar of moral character that stood against the "system". However many of his forays into international affairs proved to be dangerous brinkmanship at best and disastrous at worst (e.g., the Vietnam War, the Bay of Pigs invasion, the Cuban Missile Crisis). Along with the fact that his "monolithic conspiracy" speech may not have been referring to an Ancient Conspiracy trying to Take Over the World, but rather against Communism and the Soviet Union.
This is very common in works featuring Nikola Tesla. He is often portrayed as a super-geek fighting/being betrayed by Thomas Edison, who gets some Historical Villain Upgrades in the process. They often say that he was the sole creator of his inventions, even when he was just improving on something that came before (alternating current, for instance) or gloss over his ideas that failed simply because they were completely unworkable.
Anime & Manga
Date Masamune is played like this in many works. In real life, he may as well be categorized with Oushuu's Oda Nobunaga, he killed his brother to rise to power (his nagging mother constantly opposed him and promoted his brother for clan leader) and betrayed the alliance with the other clans without much discussion (and conquering them). He also showed little respect to Hideyoshi when he was called to join the attack on Odawara (and late to come to boot!). But in Samurai Deeper Kyo, he ends up becoming Kyo's ally, though he may be rude and brash (aka Bontenmaru). And in Sengoku Basara, he becomes the BadassJerk with a Heart of Gold hero with a somewhat charming personality and several Pet the Dog moments (seen with Kojuurou and Itsuki, or in the Drama CD, Oichi) And in Oda Nobuna no Yabou, she is a Boisterous and Large Ham who's an ally of the heroes. This one is averted in Koei's Warriors series. In Samurai Warriors 2, he comes off as a jerk, but hides a lot of ambitions that are beneficial for Japan. But in Warriors Orochi, he becomes Orochi's henchman and is pretty much loyal to him and has no qualms on bringing chaos into the world. Maybe that's his true nature.
In Fullmetal Alchemist: Conqueror of Shamballa, Fritz Lang becomes one of Ed's allies in Weimar Berlin, and is depicted as an anti-fascist Badass who opposes Nazism as early as 1923. His real-life political leanings are less well known and Lang actively obscured them with his creative retellings of his life in Germany. However, he was thrown out of at least a couple German exile parties in Hollywood for making anti-Semitic comments, and was known to be abusive to his cast and crew on set. (Granted, it's hard to expect historical accuracy from a film that depicts the Beer Hall Putsch as part of a coordinated effort to take over Germany with the help of a group attempting to open a portal into Ed's alchemical universe.) Lang putting an entire film crew into mortal danger just to get a shot of a dragon for Die Nibelungen seems fairly like him, though.
Rurouni Kenshin turns Saitou Hajime into a BadassAnti-Hero. In actual history, he did manage to survive the mess that was the Meiji revolution and became a member of Japan's secret police (pretty much their equivalent of the FBI), but Watsuki freely admits that he pretty much made up all of the other details about Saitou's personality (as a minor note, RuroKen Saitou claims to have given up drinking, while in real life he died of a stomach ulcer as a result of it).
The manga's treatment of Okubo is closer to this trope. He's historically seen as a Sleazy Politician, and that aspect is certainly part of his character, although he's presented as working for the best for his country and deserving of the respect he gets from Kenshin and Saito. Word of God comments on wanting to rehabilitate his image, noting that in terms of corruption, he wasn't much different than Japan's current politicians.
While this trope applies primarily to human beings and not machines, the eponymous Cool Starship of Uchuu Senkan Yamato counts. The real life warship may have been a Cool Boat, but battleships were being eclipsed by aircraft carriers in the Second World War and the Yamato was no exception, with no kills during the war except possibly one small escort carrier, and being ignominiously sunk by aircraft while on a one-way suicide mission. Not the most appropriate ship to undertake a voyage to save the earth.
Fate/Zero takes Alexander the Great, certainly an inspiring figure in his own right, but hardly a morally superior one, and turns him into what may be one of the most inspiring characters in anime history by giving him a complex philosophy that guides him while staying relatively true to the original Alexander's historical actions and fiery, straightforward personality, occasionally even calling him out on some of the less heroic actions of his historical counterpart. Tropes Are Not Bad indeed.
300 conveniently leaves out any mention of Spartan pederasty and slaveholding, which were major parts of their culture at the time, to keep them sympathetic to modern audiences. The film also leaves out their homosexuality and extreme devotion to religion in an attempt to appeal to gung-ho masculine audiences, going as far as having the hero criticize the Athenians as "boy lovers" and call out their own clergy as "corrupt."
Arguably, the film does actually emphasize their extreme devotion to religion, but also has Leonidas himself rejecting the practices as illogical and detrimental to them during a time of war.
Actually, Spartan homosexuality is much debated. Xenophon, Plutarch, and Aristotle all deny allegations of homosexuality among the Spartans (the lack of which was a bad thing according to Aristotle, as led to women assuming too much power in Spartan society). Additionally, check out the asterisk note on 300's page to see the nuances of pederasty between Greek city-states.
Charles Fort may be one of the most important figures in paranormal science, but he wasn't much of a hands-on investigator. The only weird event he claimed to be present for was a painting falling off a wall for no apparent reason. In a one-shot comic from Dark Horse Comics, he's not only depicted as being directly involved in the things he investigates, but is upgraded to a badass action hero who saves the world from aliens. A preteen H.P. Lovecraft gets to be his sidekick. At the end of the comic, Theodore Roosevelt puts him in charge of a secret UNIT-like organization, putting us firmly into Beethoven Was an Alien Spy territory.
The imperial Romanov family in Anastasia. Don Bluth really just grabbed the opportunity to portray another idyllic Disney-like princess, while neglecting to mention all the reasons the revolutionists thought themselves justified in their actions. On the other hand, Grigori Rasputin gets quite the Historical Villain Upgrade.
Braveheart upgraded William Wallace into the architect of Scottish Independence and downgraded Robert Bruce to little more than a background character. William Wallace raped women and burnt down schools with children and monks still inside. Robert Bruce is one of the great heroes of Scottish history and his guerrilla campaign against the forces of Kings Edward I and II was much larger, went on for much longer and was far more successful than Wallace's. Plus, it shows Bruce betraying Wallace. He never once betrayed Wallace (Everyone else, sure - but never Wallace). Wallace also never met Princess Isabella, and certaintly wasn't the father of Kind Edward III-for one, the Real Life Isabella was only a little girl at the time.
Balian in the movie is elevated from a knight who made a courageous, humanitarian decision to negotiate with Saladin into an archetypal heroic Everyman knight embodying the best of the chivalric ethos. Balian wasn't as nice as the film made him out to be. Not only was he raised a noble, not a blacksmith as he is in the film, but he betrayed his oath not to fight Saladin on more than one occasion, sold many of the peasants in the siege into slavery and threatened to massacre his Muslim prisoners if Saladin wouldn't accept a surrender.
Saladin gets a bit of a Heroic Upgrade too in the film. He's been receiving Historical Hero Upgrades from both Muslims and Christian Europeans (to whom he was a Worthy Opponent) for so long that it's probably harder to represent him badly. Ironically, the modern lionisation of Saladin flows from the European depiction of him - until the late 19th century he was mostly forgotten in the Muslim world, in large part because the empire he created barely outlived him.
The real Rob Roy was both a murderer and a cattle thief. The movie Rob Roy turns him into a heroic man of impeccable honor, though strangely it still does make passing mention to cattle-thieving (though it was a common practice in those days).
In Valkyrie, the German officer corps is implied to be exclusively against Hitler for moral reasons. The fact that many of them harbored racist, anti-Semitic and classist views is glossed over. Their objections against Hitler ranged from him being far too murderous towards the "gutter races", to empowering the lower and middle classes, to simply losing the war.
Lord Guilford Dudley in Lady Jane. In the film, despite his bad boy persona, he's actually a virgin with a passion for social justice. In reality, Guilford had a well-established reputation for being a Jerk Ass (including a widely-reported temper tantrum when, after her coronation, Jane refused to make him king). The film has him falling in love with Jane (and she with him) despite the fact that the Real Life Jane actually refused to see him on the night before his execution.
Eliot Ness of the The Untouchables. In the two TV series he's the ultimate lawman and takes down Al Capone; in the film by Brian De Palma, he's also an Action Dad whose resolve is only strengthened when Capone and Nitti threaten his loving wife and daughter. In reality, while the Untouchables put pressure on Capone's organization, and Ness weeded out the corruption in Chicago's law enforcement, it was an unrelated IRS operation that ultimately brought down Capone. Ness had no children when he was assigned to Capone (he did later adopt a son) and his first marriage failed. His later life was marked with business failures and alcoholism.
Lucilla, sister of the Roman Emperor Commodus has been given a Historical Hero Upgrade in both Gladiator and the 1964 epic The Fall of the Roman Empire (where she was played by Sophia Loren). The real life Lucilla was indeed involved in a plot to assassinate her brother... but according to contemporary historian Herodian it was because of her own jealousy and desire for power (in fact he even blames her attempt to have Commodus killed as what made him so paranoid in the first place).
Earlier in the USA's history, General Custer was often depicted as The Messiah, a brave hero who fought against the Indians and died alongside his men. This myth extended to both literature and eventually, film. This is most notable in 1941's They Died with Their Boots On. More modern sympathies with the Indians have caused him to no longer be portrayed this way, however. Custer's heroic myths are due to his wife, who outlived him (she died in 1933, a little under 60 years after him). She wrote three books depicting her late husband as a folk hero. She was afraid he would be blamed for the humiliating defeat and slaughter his troop suffered, and thus spent the rest of her life lobbying extensively to make her husband look a hero.
Chris Gardner in The Pursuit of Happyness. Although somewhat true, he was somewhat more of a Jerk Ass than he was in the film, as Cracked notes here  (quote: "he actually didn't even know where the hell his son was for the first four months of the program."
Cecil B De Mille's Samson & Delilah does this to the latter, whether she existed or not. Delilah never felt remorse for chopping off Samson's hair and removing his strength and her part in the story ends after that. His version has her truly fall in love with Samson and feel bad when he goes blind.
While not much is known about the actual personalities of any of the well-known military leaders in the Three Kingdoms period of Chinese history, they are depicted in Red Cliff as having considerably modern views on things despite living in third century CE China.
The film version of V for Vendetta paints Guy Fawkes as a Doomed Moral Victor and Tragic Hero who died to strike a blow for freedom. It fails to mention that he and the other members of the Gunpowder Plot were essentially Western Terrorists mainly interested in replacing the Protestant monarchy with a Catholic one* Although it's debatable if they could have succeeded (the majority of the country was still loyal to the crown and would most likely have resisted them in the ensuing civil war). The country would still have been worse off either way though (in the the plotters were able to get foreign backing then the British Isles would have been under the control of said power, if they lost then Puritans would have taken over and taken the Catholic burning Up to Eleven in retaliation; either way, much of the progress and freedoms of the last few hundred years would have been undone). People in the UK tend to have a neutral view of him (he's famously referred to as "the last man to enter Parliament with honest intentions"* Those intentions, of course, being to blow it up and kill everyone present. But at least he was honest about it.), since the government at the time was pretty draconian and handing out excruciating deaths rather freely. It is also notable that Fawkes was the last man brought into the plot, and was brought in due to having worked as a mercenary in Spain, which gave him the necessary Catholic sympathies and demolitions expertise.
Ironically, James I was actually pretty tolerant to Catholics, attempting to repeal some of the laws persecuting Catholics and (possibly) being married to a Catholic. Even after the Gunpowder Plot James only really went along with the stricter laws on Catholics that were passed because parliament were willing to give him a load of cash to do so. If the Gunpowder Plot hadn't happened then it's possible that James would have granted Catholics greater freedoms, as he handled religious issues remarkably well, far better than his successors.
Thirteen Days was criticized by historians and then still-living members of Kennedy's administration because the movie intensely exaggerates the role that Kenny O'Donnell (the main point of view character played by Kevin Costner) played in preventing the Cuban Missile Crisis from escalating. The chief agent in the American government who pulled the administration together during the crisis was in fact Ted Sorensen, who's instead relegated to such a minor role that he's barely noticeable.
No less a luminary than Joe Montana has criticized Rudy for far overstating his role on the team and understating how much work everyone else was putting in too.
More a mythological/literary example than a historical one, but Sun Wukong, the Monkey King in The Forbidden Kingdom. As an example, in the movie, the Jade Emperor suggests that the Monkey King could be given a bit more refinement if given an office in the Celestial Bureaucracy, which he doesn't get because of the villainous Jade Warlord. In the original story, he is given a position (albeit as Cleaner of the Heavenly Stables), and becomes even more unruly because he's pissed at it not being grand enough (namely, not being the grandest position imaginable).
John Nash and his (first) wife in A Beautiful Mind. In the film, she is still with him in the 1990's when he got his Nobel prize, making it a heterosexual triumph-of-love story. In real life, she divorced him in the 60's when he got caught hanging around in public toilets picking up young men, and he wasn't allowed to accept his Nobel onstage due to being off his meds. He did, however, reconcile with and remarry her.
The Spartans in 300. In the movie there is a lot of talk about "freedom". Real-life Ancient Sparta was governed by a system that could best be described as militaristic communism. The state was the ultimate owner of everything, with citizens being granted assets as deemed appropriate. Military teaching encouraged the use of stealth and dirty tricks. Slavery and serfdom were the norm for all non-citizens within the area ruled by Sparta. Infanticide was a common practice. Basically an Anti-Villain society.
The 1940 German film Das Herz der Königin ("The Heart of the Queen"), viewed by many critics as an anti-British propaganda movie, portrays the troubled Mary, Queen of the Scots (Zarah Leander) as a beautiful saintly martyr whose heart is full of love for her people and who wishes above all to give them freedom and happiness. She spends the majority of the film frolicking around Scottish castles in glamourous anachronistic gowns while singing pretty songs about her tragic life.
Dangerous Beauty gives this to both Veronica Franco and Marco Venier. The film portrays Franco as bravely standing up to the Inquisition (which receives a major Historical Villain Upgrade) at her trial for witchcraft, and portrays Venier as being desperately in love with her, and defending her from the Inquisition, and persuading the rest of the Venetian Senate to do so as well. In reality, Veronica Franco was never in any real danger from the Inquisition. She was actually denounced as a witch, and tried by the Inquisition, on two separate occasions. The first time, she confessed to having performed sorcerous rituals to entertain her clients, but insisted that she did not believe in them. The Inquisition's response was, in effect, 'well, that's still not really appropriate, so please don't do it anymore.' The second time, she confessed again, and once again maintained that she had only done it to entertain her clients, and not because she believed in witchcraft herself. This time, the Inquisition... responded the same way as before. The fact is, the Inquisition regarded accusations of witchcraft as silly superstition, and acquitted accused witches as a matter of course. Franco was, again, never in any real danger. The film also, in an earlier scene, depicts Franco as a hero of the Venetian republic for persuading the king of France, by being just that good in bed, to ally with Venice against the Turks. In real life, King Henry III of France did sleep with Franco when he visited Venice to negotiate the alliance, but that had nothing to do with why he allied with Venice.
Seven Years In Tibet downplays Heinrich Harrer's involvement in the Nazi Party. To be fair, he later described it as a youthful mistake and he never actually fought for the Nazis having left Europe before the start of the war. Still, the image of him insisting that he's Austrian and only reluctantly taking the Nazi flag is a false one.
Imperium: Augustus did this heavily with the eponymous Emperor and his rise to power. The movie presented him as an idealist whose goal was for the good of Rome. He also never wanted to do all the ugly things he did but was forced to because of the actions of his enemies. This was also done to a lesser extent with Julius Caesar who was presented as a Wide-Eyed Idealist.
Istvan Szabo's Colonel Redl (1985) does this for Alfred Redl, infamous Austrian spymaster-turned-traitor. Most historical accounts claim that Redl betrayed military secrets to Russia after being blackmailed for homosexuality, though a few accounts suggest he merely did it for the money. By contrast, Szabo's Redl is essentially scapegoated by officials in the Austro-Hungarian government to distract from a coup d'etat plotted by Archduke Franz Ferdinand - who conversely gets a major Historical Villain Upgrade as a bloodthirsty warmonger.
Older Than Print: The Arabian Nights gave Haroun al Rashid a Historical Hero Upgrade. The most memorable event in his real reign was his execution of a powerful aristocratic family, therefore making his empire weaker. Is it ever mentioned in the stories? Sometimes, but they don't go too far in the opposite direction to Harun himself. In most stories, he's a lovable eccentric going on fantastic adventures — except in stories featuring Ja'far ("The Three Apples" especially), in which he comes off as a bit unstable.
This is especially the case regarding on Liu Bei. True enough, he had noble goals. However, his traits have often been exaggerated to make him seem as if he was an extremely honorable man; never mind that he made lots and lots of mistakes that make him pale in comparison to Cao Cao's war abilities (such as irrationally leading the disastrous attack on Yi Ling, or slamming his infant son to the ground, effectively dooming his future empire). Yeah, author favoritism is also at fault here.
Zhuge Liang may embodies this trope even more than Liu Bei. The author portrays him as completely godlike in every way, except for the minor detail where he has to succumb to overwork in the end because history said so.
Zhao Yun gets special treatment as Liu Bei's most badass Bishounen spear-wielding hero apparently and treated like Yukimura as one of the best warriors in China.
A good deal of children's fiction about the English Civil War depicts the Royalists as being noble, flawless heroes and the Roundheads as being sly, unscrupulous villains. Adult fiction, on the other hand, often depicts the Royalists as deceitful, Frenchified, crypto-Catholic cads and the Roundheads as solid, honest, decent, beef-hearted true Englishmen. In reality, of course, both sides had legitimate points and obvious wrongs.
Mary Boleyn was characterized by in The Other Boleyn Girl as a blushing virgin who loved Henry VIII and only wanted a quiet life in the country (as opposed to her sister, who was evil by virtue of being ambitious). The real Mary was known as "The Great Prostitute" because of her promiscuity. Her family went so far as to recall her from the French court because her behavior there was scandalizing them. Anne, on the other hand, only ever slept with one guy, and look how she's remembered.
In Harry Turtledove's The Guns of the South, Nathan Bedford Forrest is portrayed as being fiery, devoted, and honorable, though his racist ideals aren't shied away from. In the first and third Acts, he is shown to be a hero for the South, and he is a Graceful Loser at the end of the Second, ultimately agreeing to serve an abolitionist who beat him in a fair election. The real Nathan Bedford Forrest is perhaps best known for being the first Grand Wizard of the Ku Klux Klan (which notably doesn't even exist in the book's altered timeline, because the CSA wins the war).
In The Hooded Riders, author J.T. Edson portrays the outlaw and gunfighter John Wesley Hardin as a wrongly accused hero, and his killing of a black man is presented as self-defence.
The Pyrates reinvents Captain Henry Avery/Long Ben Bridgeman, mutineer and pirate, as Royal Navy hero Captain Benjamin Avery. But it's not claiming to be remotely historically accurate.
The Epic of Gilgamesh may have originally been propaganda for the real King Gilgamesh of Uruk, although it likely mutated over hundreds of years, as the story as we know it paints him as very flawed (but still incredibly badass.)
There is a bit of this in the Belisarius Series. While even heroic medieval warlords behave on occasion, like — well, medieval warlords — there is more religious tolerance then is credible and Antonina's loyalty to Belisarius is raised above what some sources would indicate. Although the explanation is used by the book that much of that is malicious court gossip, and that explanation is not totally rejected by real historians.
Subverted in the fictional story "Operation Chickenhawk" in Al Franken's Rush Limbaugh Is a Big Fat Idiot, where Newt Gingrich, Dan Quayle, Rush Limbaugh, Pat Buchanan, Phil Gramm, Clarence Thomas and George Will serve in the Vietnam War (which they all avoided in Real Life), but prove to be either Dirty Cowards or dead meat.
And he smiles, but not as Sultans smile, and settles back the blade....
(But Don John of Austria rides home from the Crusade.)
Thomas Cromwell is portrayed as a slightly better man in Wolf Hall than he would have been in real life, although not nearly as much as it might seem - most other depictions of him fall into the Historical Villain Upgrade variety.
Doctor Who gives this treatment to Vincent van Gogh in "Vincent and the Doctor". Ol' Vinny goes from a tortured painter to Bad Asshunter of invisible monsters who eventually kills the Monster of the Week by impaling it on the anchor spikes of his easel. Other historical figures that the Doctor encounters in his travels get this trope in smaller doses as well: Shakespeare, Queen Elizabeth, Agatha Christie, Churchill...
Although Van Gogh is depicted as a tortured painter as well who still dies of madness even after learning of future success.
The Tudors does this with Anne Boleyn and Thomas Cromwell. Anne in fiction is usually portrayed as a scheming whore, while Cromwell is often made pure evil. The show portrays Anne as being honestly in love with Henry and a devoted mother. Cromwell, while still rather ruthless, is seen as very human, and quite sympathetic.
To be fair, Anne is also depicted as intending (at least at first) to manipulate Henry using both lust and love, and to maneuver him into serving the schemes of her father, a notable member of Henry's court, long before she begins to legitimately care for him. Both depictions are much more morally gray than normal, and as such, probably a more accurate depiction of real people, at least morally if not historically.
She is also portrayed as having slept with Sir Thomas Wyatt before her marriage with Henry VIII. There are indications Wyatt may have had romantic feelings for her, though there is no proof that Anne reciprocated, and certainly not that they had sex, as it would have gravely endangered any future marriage of Anne's if she were found to not be a virgin. Wyatt was arrested for adultery with Anne, writing a poem about witnessing the beheadings of Anne and her co-defendants from his cell window in the Tower of London, but released a year later. There's no evidence any of the charges Anne was convicted on (that included incest with her brother) were anything more than trumped-up.
If anything, Anne was more fairly depicted in The Tudors—though her sex life is probably exaggerated—while Cromwell is, for once, treated as a human being. He's usually given a Historical Villain Upgrade due to the exultation of Thomas More. (Who, while in actuality being quite judgmental and sometimes extreme, was given his typical Historical Hero Upgrade in The Tudors.)
Not quite-they don't sugarcoat his hatred of Lutherans, and show him overseeing people being burned at the stake.
Al Swearengen actually debuted with a Historical Villain Upgrade in the pilot episode of Deadwood, engineering a massacre of Swedish immigrants and blaming it on the Indians (its historical explanation). For additional horror, the immigrant party was turned into a family with cute children and Swearengen wanted to kill the Sole Survivor little girl to cover his tracks. But Ian McShane's praised portrayal of the character, implying that he had a soft spot underneath, convinced the writers to tone down the character and give him more sympathetic traits halfway through the first season, while his most detestable ones were transferred to the owner of the saloon across the street, Cy Tolliver. By the third season Swearengen is almost a messianic figure that recruits his whores in orphanages in an attempt to save them from having a terrible childhood like he had, cries because his mom abandoned him as a child and teams up with straight hero Seth Bullock to save the camp from robber baron George Hearst. The real Swearengen actually made money offering young women jobs as cooks or maids and then press-ganging them into white slavery.
I, Claudius single-handedly rehabilitated the reputation of the Emperor Claudius, who was long thought of as just another cruel despot among the Roman Emperors, is now rather positively viewed in the popular imagination. Although the idea that he, along with several other characters in the series, wished to restore the Republic is pure fabrication. In their eyes, the Republic never collapsed, with Augustus and his successors simply being princeps, or 'first among equals'. It wouldn't be until Commodus' reign that the senate began it's true slide into irrelevance.
Henry V ignores several inconvenient aspects of the historical king, probably because he was a badass warrior King of England at a time when English nationalism was on the rise after hundreds of years of domination by French overlords. Still, he could easily have been seen as a villain, even by the Elizabethans. He executed captured enemy knights, presided over some horrible bloodbaths, doomed both sides to keep fighting a pointless war, burned "Protestant" heretics* strictly speaking, Lollards, but these were seen as Protestant forerunners by many Elizabethans alive — including Sir John Oldcastle, the original of Shakespeare's Falstaff — andhad a nasty scar across his face.
Henry VIII ends with Henry and Anne eagerly expecting his heir, the future Queen Elizabeth - ignoring the fact that the entire point of the exercise had been for Henry to get a male heir, and indeed that Catherine had already borne a female heir (who would grow up to be Bloody Mary)... not to mention the infamous mess that would come a few years later, with Catherine dead and Anne convicted of capital crimes, both under very suspicious circumstances.
Thomas More's portrayal in A Man For All Seasons tends to focus on his bravery in maintaining his principles even when he knew this would result in his gruesome death, presenting him as a champion of the freedom of the individual conscience. Even apart, however, from the Values Dissonance that led him (like nearly everyone in his own time) to approve the burning of heretics, More was fully convinced that the state had a perfect right to suppress any open dissent; his entire defense was based upon the plea that he had not made his personal opinions known. He was definitely no advocate of free speech, as the play seems to suggest he was.
The Cirque du Soleil shows based on Michael Jackson's work, Michael Jackson THEIMMORTAL World Tour and Michael Jackson ONE portray him as a transcendentally gifted performer and humanitarian. In the latter show, his iconic costume items magically grant people his core attributes — playfulness, agility, courage, and love — and the primary antagonists represent a Strawman News Media out to tear him down. As one might imagine, his myriad personal failings — egotism, drug abuse, plastic surgery to the point of Body Horror, the lingering question of whether he was a pedophile or not, etc. — are swept under the rug; even before ONE opened, Steve Bornfeld questioned this portrayal (which is the standard one amongst the more rabid Jackson fans, keep in mind): "[Cirque's] predecessor shows honored the brilliant music of The Beatles and Presley without suggesting that its subjects wrapped their arms around the globe and cradled it in its loving embrace." He also points out that the image of Michael as a champion of goodness and the world's greatest entertainer was one he cultivated to begin with (as in the Forced Meme "The King of Pop").
Oda Nobunaga is typically portrayed as villainous in most Japanese Historical Fiction, but from Samurai Warriors 2 onwards he gets treated as a pragmatic Anti-Hero. Historically, he was much closer to the game's portrayal of Hashiba Hideyoshi as an eccentric yet highly general and administrator. He was not only a ruthless commander, but embraced Western culture and technology before most other Daimyos and implemented several important policies that are still used or directly influence current policy today. Embracing the use of guns allowed him to rout his opponents in battle.
No mention of Toyotomi Hideyoshi? His character in Samurai Warriors depict him as, while prone to silly antics at times, is an ultimately good guy who wishes for everyone to be happy and inspired loyalty from great warriors like Yukimura Sanada. The game failed to mention his brutal persecution of Christianity, crucifixion of the 26 missionaries sent to Japan, invasion of Korea (and his attempt to do the same to China), and the imposition of rigid social classes that halted the social mobility from which he himself had benefitted. The Korean invasion being omitted may be justified because KOEI wouldn't dare piss on the Korean due to the bad blood between them and Japanese (which was Hideyoshi's fault), but the rest of the omissions still counts, even Hideyoshi has some bonds with some Chinese warriors in Warriors Orochi (Although these Chinese people was in a time before Hideyoshi was born or could even invade)
In the 2nd 3DS game, they introduced Yagyu Munenori, badass swordsman of the Yagyu clan who usually is portrayed as villainous or an utter bastard. In this game, he's said to be possessing none of those overexaggerated bastardizations and is an all around just and honorable swordsman.
Pretty much everyone in the Sengoku Basara series that wasn't instead made into an outright villain gets some degree or another of this, but Tokugawa Ieyasu is the biggest — by Sengoku Basara 3 he's basically The Messiah, compassionate and honest, and his Power Fist combat style is symbolic of his desire to keep war from ever again severing the Bonds between people, rather than power-hungry and manipulative. Not to mention, he's a young Bishōnen rather his usual portrayal of being a fat old man.
To a lesser degree, his son Liu Shan is also portrayed as, while far from the warrior his father was, a man of virtue.
Sima Zhao also gets this, as he was much worse in real life. Zhuge Dan's bio in the game even suggests that Zhao's rule was Tyrannical.
A prime example of this is during Zhuge Dan's rebellion after Dan killed Wen Qin. Zhao states that any soldiers who willing surrenders would be unharmed while Zhong Hui suggests that they should just kill them, when historically it was the other way around.
For starters, the Hashshashin themselves. IRL(as far as we know), they were Hassan-I-Sabah's private army, and brainwashed with drugs to boot. They built a reputation at the time as his enemies were Asshole Victims who they eliminated with a minimum of collateral damage.
There is no Real Life proof of their supposed drug-use, only hearsay from their foes. But they definitely were ruthless religious fanatic, not entirely unlike the modern terrorists.
King Richard I of England, however, got a fairly realistic representation: he went by the title "Lionhearted" even in his own day, and it did not refer to heroism but a love of combat. So, though he's driven to conquer Jerusalem, he keeps his promise to listen to Altaďr finally after he beats Robert De Sable in single combat, and lets Altair go free afterwards. He's undeniably a jerkass, but he's still portrayed in a relatively positive manner - basically a Noble Demon.
Lorenzo de'Medici is portrayed as being a devout republican and a benevolent ruler. In reality, like all the noble families in the Italian city-states, the Medicis were Machiavellian schemers who committed all sorts of immoral acts to maintain their power. At least it's shown in Lineage short how Lorenzo brutally tortures an agent of his enemies for information, and in Brotherhood Lucrezia Borgia claims, probably truthfully that he quashes the families of his rivals utterly, even those who had nothing to do with the plots against him.
And who can forget how Leonardo da Vinci got an upgrade in heroism, despite only being the sort-of deuteragonist? Notable changes include that his inventions work, are completely functional and can be used at nearly any time. Plus he's the main character's BFF.
According to some fan-theories, the events of the games are filtered through Altair and Ezio's impressions of them. Such as the way beggars in AC 1 would bother Altair and only Altair.
Not to mention that with their advantage in information control, the Templars would obviously try to slander any historical figure who allied themselves with the Assassins.
Call of Duty: Black Ops 2 gives one to Angolan rebel leader Jonas Savimbi. In the game, he's a gregarious and enthusiastic player ally who rides into battle at the head of his army and even pulls off a spectacular Gunship Rescue at the end of the mission he's featured in. In real life, he was a war criminal who massacred civilians, funded his army by selling conflict diamonds, accepted military aid from apartheid South Africa, ran the territories he controlled like his own personal kingdom, ordered the torture and execution of his own men if he suspected them of betrayal, and re-started the civil war twice after previously agreeing to ceasefires because he didn't win the post-war elections (it took his death in battle with government troops to finally bring the war to an end).
Played with hilariously in Time Squad. When the team is given a mission, Otto always would get really excited and start rattling off the wonderful achievements of whoever it was they were going to meet, pretty much ignoring any of the flaws (arguably justified through childish idealism). When they actually meet the historic figures however, they are all stupid, insane, stubborn, cruel, or plain incompetent.
One example that stands out, though, is Josef Stalin. In Real Life a mass-murdering megalomaniac who became the Token Evil Teammate for the Allies only after his Villain Team-Up with Adolf Hitler ended in a German invasion of Russia, his appearance in the show is limited to a small role and passing mention as one of the leaders of World War 2, and painting him, Churchill and Roosevelt as Best Friends Forever rather than reluctant allies- in Real Life, roughly speaking, Churchill was annoyed with Roosevelt and increasingly worried about Stalin; Roosevelt was annoyed with Churchill and rather naively trusted Stalin; and Stalin liked both of them and enjoyed manipulating them even more. In the show, Stalin and Roosevelt decide to forgo clothes and become nudists upon prompting from Churchill. Of course, this is Time Squad - the show where Mahatma Gandhi is tap-dancing in a far-future space station's prison cell because he refuses to stop doing that and start with the whole Indian independence movement - so historical accuracy is not a priority.
Columbus' heroic reputation is actually Averted in, of all places, an episode of The Flintstones dealing with Time Travel. While the mythical story of him trying to prove the world is round is kept, here he's portrayed as a Jerkass and a Mean Boss towards his crew (and the four members of the cast) who has to fend off an attempt at a mutiny while threatening the four cast members to help him. The mutiny is stopped when Wilma sees land... And he quickly takes credit for it. (Fortunately for the four protagonists, the Time Machine starts working again and whisks them to a new time period, but they only find more trouble there.)
Lei Feng was an ordinary but not particularly notable soldier in the People's Liberation Army. Then he died, and, amazingly, it turned out he just happened to have written a big diary in which he had recorded his dutiful life devoted to Chairman Mao. Most historians are pretty sure that the entire thing was a result of the Communist Party's Propaganda Machine.
Similarly, Nicolas Chauvin, if he really existed, got this treatment from French Bonapartists. Ironically, today he would generally get a Historical Villain Upgrade due to being the origin of the word "chauvinism".
Many of the Saints in the Catholic Church were often unsaintly. To a large degree that is because the colloquial idea of a saint is different from the official idea of a saint; it is after all official doctrine that sinning is part of being human even if you are a saint. Thus they often got upgraded mostly by popular tradition rather then official tradition.
In the Church's defense, part of the reason the Saints are meant to be venerated is because they turned away from unsaintly behavior, rather than being pure to begin with, which is what fellow man needs to strive for. It also helps that the Church also teaches in original sin, in that all people are born sinful (with Jesus and Mary being the sole two exceptions.)
Sayonara, Zetsubou-Sensei has an instance wherein during a lecture on the importance of holding one's tongue, Nozomu speaks positively about Kira, the man traditionally viewed as the villain in The 47 Ronin incident. Nozomu refers to him as a cultured man taken advantage of by a bunch of bumpkins.
At the end of Fullmetal Alchemist, the heroes have to whitewash Führer Bradley's life and not tell anyone that he was a Homunculus and willing to sacrifice his people to give Father godhood.
The second prequel series of Legend of Galactic Heroes has a younger Yang Wenli trying to research the life of one Bruce Ashbey, a famous Alliance war-hero. The arc itself is a discussion of this trope, with Yang lampshading the fact that while Ashbey, admirable as he was, may not have been the great badass people remember him to be, it would be foolish to automatically assume the opposite just to say that his interpretation is "unique."
Naruto: The Uchiha Clan. The village at large sees them as a great and noble clan that were victims of their traitorous prodigy, Itachi. The truth of the matter is that the Uchiha Clan was extremely bitter about their lack of power in the politics of the village despite being politically the most powerful clan due to their Military Police position, and about the perceived discrimination they suffered during the Second Hokage's reign and after the Kyuubi attack. It eventually led them to plan a coup against the village, which forced Itachi to kill them all. It should be noted that Itachi WANTED the massacre if it meant that Sasuke wouldn't live with his clan's crimes on his shoulders, and would rebuild the Uchiha to be truly noble after "avenging" their deaths. When Sasuke found all of this out, his reaction was a bit... extreme.
Films — Live-Action
Star Trek: First Contact explores this trope with the fictional historical figure of Zefram Cochrane. Federation history paints Cochrane as a shining paragon of idealism while he was really a selfish, cynical drunk (but still kind of a Loveable Rogue). Much of his widely known idealism only came long after he'd made First Contact, while the time-traveling crew only met the earlier, broken man who'd barely lived through World War 3. The Cochrane they meet even sneers at the very same aphorisms he'll later famously deliver. The novelization hints that he may have had untreated bipolar disorder, alternating between manic creative highs that led to his inventing the warp drive and crushing lows.
CIAPHAS CAIN, HERO OF THE IMPERIUM! Pretty much the poster boy for this trope: a cowardly, manipulative political officer who gets thrown into death and destruction at every turn, and comes out as a hero for the Imperium, even revered as an aspect of the god-emperor of mankind in some circles. He doesn't believe all the hype, though.
A recurring theme in the books is Cain using his memoirs (compiled into the books we read) to give himself a Historical Villain Upgrade instead. By his actions, Cain is a hero. By his own claims he's a self-serving coward. Those tropes get played with a lot, and Sandy Mitchell says he's not sure.
Within the Dragaera series, the Dumas-recycling novels Brust attributes to Paarfi are an example of this (and probably Historical Villain Upgrade as well) in universe. Paari presents a rose-colored, Good Old Ways view of Dragaeran history and tends to present historical figures in a flattering light, although in some cases, you can read between the lines and sense the real person was much less pleasant.
In the Belisarius Series, there are a couple of comments lampshading this, in which it is said that a character who died in battle would become an epic hero. In one of those cases King Eon of Ethiopia says that about himself as he is dying (ironically Eon's case is a subversion; his behavior clearly was heroic enough to win him such an honor, it simply lacked military professionalism as might be expected for so young a Warrior Prince).
An episode of The Brady Bunch showed Bobby idolizing Old West gunman Jesse James. His worried parents take him to meet one of James's victims, after which he has a nightmare in which James murders his entire family. That cures him.
Earlier in the same episode, they watch a movie based on Jessie James, but it had been Bowlderized due to TV censorship, leading Bobby to believe that James was not violent.
Jayne Cobb in Firefly. On a backwater planet of mud-cultivating peasants, Jayne apparently stole a fortune from the local tyrant, but was forced to jettison the cargo from his damaged ship. It landed near the homes of the 'Mudders', who assumed he had done it on purpose. Stories were told and songs were sung about the legendary Jayne Cobb, folk hero. Even when the Mudders are told the truth, some of them are so loyal to the idea of their hero that they prefer to stick to the old story.
The original Star Trek invokes this trope by establishing that some people in the 23rd century consider Khan Noonien Singh to be one of history's heroes.
In the Star Trek: Voyager episode "Living Witness", the ancestors of an alien civilization are treated this way after they tried to raid Voyager and took hostages while doing so. Voyager was trading with one of their enemies while not knowing there was even a conflict between the two sides, and both are given a corresponding Historical Villain Upgrade to the point that they launched a horrific war against their "peace-loving" culture and staged full-on genocide against them. They themselves, on the other hand, are depicted as martyrs and freedom-fighters.
On the series True Blood, 3000 year old vampire Russell Edgington claims that he once met Jesus, who was just a "boring hippie who stank of patchouli."
Pelineal Whitestrake in The Elder Scrolls series is known as the Divine Crusader, and held in high regard by Imperials for freeing Tamriel from the Ayleids. Nevermind he was a racist berserker who would often go into psychopathic episodes, which were said to have damaged the lands themself. He nearly single-handedly wiped an entire race from the face of the planet, and even attacked another race called the Khajiit, simply because they didn't look human.
The Dragonborn is revered in Skyrim for being a great hero, the ultimate warrior and the pinnacle of what a Nord should aspire to be. Despite it being revealed that the First Dragonborn was actually a Dragon-Priest who Turned Against Their Masters and ruled over Solstheim as a tyrant. However, this is somewhat of an subversion, since the Ancient Nord legends didn't refer to them at all, but actually the Last Dragonborn, prophecied to appear when Alduin returned. This bizarrely makes it a case of Future Historical Hero Upgrade!
Tiber Septim, first Emperor of the current Empire and the man who united the entire continent, is seen as one of the greatest men to ever live and is so beloved by the humans of Tamriel that he has become revered as the god Talos, even usurping the position of head of the Nordic pantheon. In reality though, many of his most well-known exploits can be attributed to someone else, he may have been responsible for murdering his king in order to become emperor, and he almost certainly betrayed and killed one of his closest advisors in order to power the Numidium and conquer the rest of Tamriel. Of course, the worship of him isn't entirely unfounded, as there is evidence that he really did ascend to godhood... and may be one of the last things holding the universe together.
In Final Fantasy Tactics, the official history records Delita as a hero, even though he left quite a body count on the way to the throne.
The protagonist of MediEvil, Sir Daniel Fortesque, became a friend of the king through various exaggerated tales of his exploits. When an actual battle occurred, Daniel ended up getting killed by arrows minutes into it. However, due to being the King's friend, he went down in history as a hero. When the evil sorceror he fought against tries to take over the world again, Sir Dan gets a chance to finally prove himself as the hero history remembers him as.
Raven King Naesala gets this in Fire Emblem Awakening. Specifically, in Olivia's supports with Donnel she sings a song about his romance with the heron princess Leanne. While this is true, the song reduces the story to a fairy-tale style romance (and "downgrades" Naesala to a prince), conveniently leaving out some of his more...questionable deeds, such as his Chronic Backstabbing Disorder, selling his best friend into slavery and piratical raids on any human ships entering his territory.
"1776! It ain't accurate, but it'll blow your fucking mind!"
Jebediah Springfield on The Simpsons. Touted as an archetypal pioneer who killed bears with his bare hands, he was in fact a German pirate who once tried to off George Washington but got his ass kicked.
And even before that was revealed, the narrator of the TV recreation showing a man dressed as a pioneer fighting a man in a bear suit says: " but modern historians think that was the bear who killed him
One episode of the Fairly OddParents has Timmy wanting to make a parade float based on legendary Dimmsdale founder Dale Dimm; AJ scoffs at him, declaring Dale Dimm to be just a legend and wanting to base their float on Alden Bitterroot, who is given actual historical credit for founding Dimmsdale. It turns out they both sucked. When Timmy travels back in time, it turns out Dale IS real, but a moron who is an accidental Idiot Hero AT BEST, and Alden Bitterroot is an obbessive and delusional witch hunter, identical ancestor of Crocker (who is actually a real witch himself and even more of an evil pain than his Identical Grandson!).