This trope is when a real-life historical event is revealed to have a fictional cause behind it in a work. This can be due to a case of Been There, Shaped History in some cases.
This may be done to lend a darker context to tragic historical events.
Compare Beethoven Was an Alien Spy (with real people instead of events), Been There, Shaped History and Historical In-Joke (which can overlap). Also compare Fictionalized Death Account, and also We Didn't Start the Führer and Demon King Nobunaga for when this is combined with a Historical Villain Upgrade. Related to Famously Mundane, Fictionally Magical, where a Real Life object has greater significance in fiction.
A supertrope to The Tunguska Event, Phlebotinum Killed the Dinosaurs, Caused the Big Bang, Who Shot JFK?, Alternate Landmark History and Historical Rap Sheet (when an In-Universe Big Bad is mentioned to have caused, or at least been part of, some historical atrocity or disaster).
- In Neon Genesis Evangelion, the Giant Impact (also known as "First Impact" in-universe) is stated to have been the result of Lilith's starfaring vessel, the Black Moon, crashing into primordial Earth about 4 billion years ago, with said vessel's rocky exterior separating from the vessel and coalescing into the Moon; as for the real-life explanation, it's a cover-up story by Seele in-universe.
- Rurouni Kenshin does this with the assassination of Okubo Toshimichi. In real life, Okubo was assassinated by a group of samurai unhappy with his rapid modernization/westernization and abolition of the privileges the samurai had enjoyed. In the story, Social Darwinist Shishio has his dragon assassinate Okubo as a step to weaken Japan and make it easy for Shishio to take over the country, and the samurai find Okubo's body afterward and claim credit for the deed.
- In Abraham Lincoln: Vampire Hunter, the American Civil War was caused partly because the vampires want to support the Confederacy's racism policy against the black people, as the vampires feed from those people. The war also has vampires becoming the Confederacy's troops.
- In Forrest Gump, the titular character is an Accidental Hero who routinely shapes history by being at exactly the right place at the precise time. Who discovered the Watergate burglary? Gump. Who sparked the T-shirt phrase "shit happens?" Gump. Who designed The '60s Smiley Face? Gump. If it's a critical juncture in American history, Forrest Gump went jogging through it.
- According to Men in Black, the 1977 New York Blackout was caused by an alien releasing a Hyper-Destructive Bouncing Ball into the area as a prank.
- According to Space Jam, Michael Jordan returned to the Chicago Bulls after saving the Looney Tunes from a horrible fate, because Charles Barkley, Muggsy Bogues, Shawn Bradley, Patrick Ewing and Larry Johnson believed he couldn't play the game any more.
Podolak: Did you hear that, Michael? They think you can't play basketball any more.
Jordan: Only one way to find out.
- In Wonder Woman (2017), Diana hypothesizes that World War I is caused by Ares' influence on humanity. It's actually zig-zagged. Ares may have given humanity the means to destroy each other, but humans decided to go to war all on their own. That said, Ares actually was manipulating things in an attempt to lead towards World War II, but had no role in its actual occurrence, as he was long dead by then.
- X-Men Film Series:
- X-Men Origins: Wolverine has a fictionalised version of the Three Mile Island incident, in which the nuclear plant is actually a secret laboratory for mutant experimentation, and a fight between Wolverine, Sabretooth and Weapon XI caused one of the plant's cooling towers to collapse.
- In X-Men: First Class, the Cuban Missile Crisis was instigated by Sebastian Shaw as part of his plan to have mutantkind become widespread from the nuclear fallout and dominate over humans.
- In sci-fi/horror novel DARLAH, the NASA lunar missions were discontinued not because of dwindling funding and public interest, as in real life, but because of dangerous and possibly supernatural happenings on the Moon.
- In The Divine Comedy, one saint on Venus attributes the creation of Florence to the Devil.
- The Dresden Files: Ebenezar McCoy has claimed responsibility for not only Tunguska, but also the New Madrid earthquake of 1812 and Krakatoa.
- A Net of Dawn and Bones has several catastrophes as being the result of a sorcerer managing to complete a Demongate. The Great Fire of London and the 1692 Jamaican Earthquake were both the result of Demongates opening while being opposed. The 1257 Mount Rinjani explosion was the last Demongate to open unopposed, and while it was later sealed by Heroic Sacrifice it still released enough curses to cause the catastrophes that occurred in the next few centuries, including the Black Death.
- The Pendragon Adventure: In The Never War, the Hindenburg disaster was the result of a mobster igniting it with a firework to destroy his rival's fortune, which was secretly on board.
- In the first Percy Jackson and the Olympians novel, it's revealed that World War II was basically a case of the children of Zeus and Poseidon (part of the Allies) fighting against the children of Hades (part of the Axis). This was actually the reason that Zeus, Poseidon and Hades agreed not to have any more children, as they were too powerful. Zeus and Poseidon violated their agreement, however.
- The Heroes of Olympus reveals that the American Revolutionary War and American Civil War were caused by Roman and Greek Demigods fighting for supremacy. During the former, the Romans sided with the British, and the Greeks sided with the Americans. During the latter, most Romans sided with the South, and most Greeks sided with the Union, but not all in either case, in line with that war being "brother against brother".
- Serpent (part of the Kurt Austin Adventures) opens with the sinking of the Andrea Doria. In this version, the sinking was deliberate on the part of the Stockholm's helmsman. It isn't explained why until later.
- Several episodes of Dark Skies purport that various events of The '60s were a result of the alien conspiracy. For example, the accidental activation of an alien device is blamed for the 1964 earthquake in Homer, Alaska.
- Doctor Who is full of scenes in all its history when the Doctor, as well some of his many companions, inspired or accidentally provoked various facts in history. A good example is the First Doctor in "The Romans", who accidentally inspires Nero to burn Rome.
- A short list includes the inclusion of the word Sycorax in a Shakespearean play, the KT Boundary event that killed the dinosaurs (poor Adric), at least two of Van Gogh's paintings, the brief disappearance of Agatha Christie, and, at least according to the Doctor, the creation of Yorkshire Pudding. He was not, however, Beethoven.
- The Star Trek: Voyager episode "The Thirty-Sevens" had Amelia Earhart and her crew be found on a planet by Captain Janeway and her crew, having been frozen in a deep sleep for four-hundred years.
- Alternity campaign setting Dark*Matter core rules. When a Grey spaceship on Earth was close to being discovered by humans, its commander followed standard procedure and re-directed a comet to impact and destroy the landing site. He made a mistake, and the result was The Tunguska Event.
- In Call of Cthulhu, The Tunguska Event was caused by Azathoth (one of the Cthulhu Mythos deities) being summoned to Earth.
- In the Assassin's Creed series, nearly every major event in human history, from wars to assassinations to the rise of capitalism, was engineered or affected by the Secret War between Templars and Assassins.
- According to Empire Earth II, the Cold War really ended when the U.S. stole the stealth bomber the Soviets had developed and used it against them.
- In Touhou, the failure of the Apollo 13 mission is caused by Lunarians who don't want Earthlings on the moon.
- Vampyr: The 1666 Great Fire of London was caused when vampire knight Sir William Marshall fought against a witch responsible for The Black Death in the city the year before (in reality, she was a Disaster, another of the Red Queen's minions. The battle lasted for hours to a stalemate, so Marshall was forced to trap her under St. Paul's Cathedral and set it on fire to make sure she was dead.
- In the Watch_Dogs series, the 2003 blackout that took place in the Northeastern and Midwestern United States and the Canadian province on Ontario was due to a rogue hacker instead of a software bug found in the computers of FirstEnergy Corporation. This gave Blume Corp. the opportunity to provide ctOS with a safeguard against future incidents.
- The SCP Foundation has many of these, which usually double as Historical In-Jokes:
- The explosion of Mount St. Helens was caused by a SCP-076 containment breach.
- SCP-081 caused all recorded instances of spontaneous human combustion.
- SCP-089 has announced and prevented (or at least reduced the impact of) many disasters throughout history, such as the Great New Orleans Fire of 1788, the 1970 Bhola cyclone and the Taiping Rebellion. However, it's unclear if the SCP actually causes the disasters or merely offers an extreme means of stopping them (involving sacrificing a baby to it).
- Both the image and the redacted clues show that SCP-435 was responsible for Castle Bravo, the largest American nuclear detonation.
- SCP-453 caused the Great Neapolitan Earthquake.
- SCP-687 apparently caused the Cleveland Torso Murders.
- SCP-1120: It's revealed that the eruption of Vesuvius was caused by a man who was trying to bury the numerous instances of SCP-1120 in the ashes before they overran any more towns.
- SCP-1529 is apparently responsible for killing the first man to ever climb Mt. Everest and about half of all the people who've died climbing it since.
- SCP-1574 is implied to have some connection to the Boxing Day Tsunami, despite being on the other side of the world. It may or may not have been caused by aliens from its home planet who had come looking for it.