In the year 1952, a group of hunters traveled back to the Late Cretaceous period to hunt dinosaurs that were already dying of natural causes. They were instructed to stay on a levitating antigravity path that touched nothing, yet one hunter stumbled off the path and inadvertently crushed a butterfly. When the group returned to their present, history had become significantly harsher, and a fascist was now President. This event, described in Ray Bradbury's classic short story A Sound of Thunder, became the defining metaphor for the alternate history genre, illustrating how a single, tiny change in the past could ripple forward to create a completely different future. The story established the core premise that history is fragile and that the smallest deviation can lead to a world unrecognizable from our own. This concept of the point of divergence, or POD, remains the engine of the genre, driving stories that explore the consequences of altering pivotal moments in human history.
From Livy to Napoleon
The roots of alternate history stretch back to antiquity, where Roman historian Livy contemplated an alternative fourth century BC in which Alexander the Great had survived to attack Europe as he had planned. Livy asked what would have been the results for Rome if she had been engaged in a war with Alexander, concluding that the Romans would likely have defeated him. Even earlier, Herodotus's Histories contained speculative material that questioned the inevitability of historical outcomes. In the 11th century, Cardinal Peter Damian explored the limits of divine power in his work De Divina Omnipotentia, asking whether God could change the past, such as bringing it about that Rome was never founded. The first work of fiction detailing an alternate history was Joanot Martorell's 1490 epic romance Tirant lo Blanch, which told the story of a knight who saved Constantinople from Islamic conquest. By the 19th century, Louis Geoffroy's Histoire de la Monarchie universelle imagined Napoleon's First French Empire emerging victorious in the French invasion of Russia in 1812 and in an invasion of England in 1814, later unifying the world under Bonaparte's rule. These early works laid the groundwork for a genre that would eventually become a staple of speculative fiction.
The Pulp Era and Time Travel
The 1930s marked a turning point when alternate history moved into a new arena, with Murray Leinster's Sidewise in Time published in 1934 introducing the idea that pieces of Earth traded places with their analogs from different timelines. This story followed Professor Minott and his students from a fictitious Robinson College as they wandered through analogues of worlds that followed a different history, establishing the concept of cross-time travel as a plot device. The period around World War II saw the publication of L. Sprague de Camp's Lest Darkness Fall, in which an American academic traveled to Italy at the time of the Byzantine invasion of the Ostrogoths and made permanent historical changes. Ward Moore's Bring the Jubilee, published in 1953, featured a protagonist who lived in an alternate history where the Confederacy had won the American Civil War and traveled backward through time to bring about a Union victory at the Battle of Gettysburg. These stories introduced the notion of a time patrol, where guardians moved through time to preserve the correct history, a theme that would become a staple of the genre. The era also saw the development of the many-worlds theory, which suggested that every decision that could be made differently would result in a different timeline, creating a multiverse of possibilities.
Perhaps the most incessantly explored theme in popular alternate history focuses on the aftermath of an Axis victory in World War II. In Robert Harris's Fatherland, published in 1992, the story is set in Europe following the Nazi victory, where an American reporter discovers proof of the long-denied Final Solution. Philip K. Dick's The Man in the High Castle, published in 1962, depicts a divided United States where the Empire of Japan takes the Pacific states and Nazi Germany takes the East Coast, with the remnants of the old United States' government as a Neutral Zone. These works reflect the cultural anxiety of the Cold War era, where the threat of nuclear annihilation and the possibility of totalitarian regimes taking hold were real concerns. The genre provided a way to explore the consequences of history going wrong, often focusing on the moral and ethical implications of such a world. In some versions, the Nazis and/or Axis powers win, or in others, they conquer most of the world but a Fortress America exists under siege. The theme of a Nazi/Japanese Cold War comparable to the US/Soviet equivalent in our timeline became a common trope, allowing authors to examine the darkest possibilities of human history.
Magic and the Secret History
Alternate history often shades off into other fantasy subgenres when the use of actual, though altered, history and geography decreases, though a culture may still be clearly the original source. In Poul Anderson's Three Hearts and Three Lions, the Matter of France is history and the fairy folk are real and powerful. Randall Garrett's Lord Darcy series presents a point of divergence where a monk systemizes magic rather than science, so the use of foxglove to treat heart disease is regarded as superstition. Another point of divergence occurs in 1199, when Richard the Lionheart survives the Siege of Chaluz and returns to England, making the Angevin Empire so strong that it survives into the 20th century. Jonathan Strange & Mr Norrell by Susanna Clarke takes place in an England where a separate Kingdom ruled by the Raven King and founded on magic existed in Northumbria for over 300 years. These works explore the idea that magic could have been real and that history could have taken a different path if certain events had occurred differently. The genre allows for the exploration of secret histories, where modern-day worlds no longer believe that these elements ever existed, yet they were present all along in a different form.
The Digital Age and Fan Communities
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. The Usenet Alternate History List was first posted on the 11th of April 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, the self-described largest gathering of alternate history fans on the internet with over 10,000 active members. 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. These online communities have allowed fans to share their own works, discuss the genre, and explore the vast array of alternate histories that have been created. The internet has become a vital resource for the genre, providing a platform for both established and emerging authors to reach a global audience.
Television and the Multiverse
Television has become a major medium for alternate history, with shows like 1983 set on a world where the Iron Curtain never fell and the Cold War continues until the present. The Englishman's Castle tells the story of the writer of a soap opera in a 1970s England which lost World War II, where England is run by a collaborator government which strains to maintain a normal appearance of British life. The Community episode Remedial Chaos Theory created six different alternative worlds, with characters from the worst universe, the darkest timeline, later appearing in the prime universe. The Marvel Cinematic Universe series Loki and What If...? show alternate universes that depict alternate events from MCU films, while The Man in the High Castle, an adaptation of the novel of the same name, showed a world where the Axis Powers won World War II. These shows explore the concept of the multiverse, where every decision that could be made differently results in a different timeline. The genre has expanded to include a wide range of themes, from the consequences of historical events to the exploration of secret histories and the moral implications of such worlds.
The Future of What If
The genre continues to evolve, with contemporary works exploring new themes and settings. Kim Stanley Robinson's The Years of Rice and Salt starts at the point of divergence with Timur turning his army away from Europe, and the Black Death has killed 99% of Europe's population, instead of only a third. Philip Roth's The Plot Against America 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 a US that features increasing fascism and anti-Semitism. Michael Chabon's The Yiddish Policemen's Union 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. These works demonstrate the genre's ability to explore a wide range of historical periods and themes, from the consequences of historical events to the exploration of secret histories and the moral implications of such worlds. The genre continues to thrive, with new authors and works pushing the boundaries of what is possible in alternate history.