Alternate history is a type of genre fiction consisting of stories set in worlds in which history has diverged from the actual history of the world, changing one major event and progressing down a different path. It has been seen as a subgenre of literary fiction, science fiction, and historical fiction. Some alternate history works have been known to use tropes from any or all of these genres. Alternate history is not to be mistaken with counterfactual history. Counterfactual history is a term used by some professional historians. They use thoroughly researched and carefully reasoned speculations on “what might have happened if…” as a tool of academic historical research.
Since the 1950s, this type of fiction has to some extent merged with science fiction including cross-time travel between alternate histories or psychic awareness of the existence of “our” universe by the people in another or ordinary voyaging that results in history splitting into two or more timelines.
The earliest example of an alternate history is Book IX, sections 17–19, of Livy’s Ab Urbe Condita. Livy theorized an alternative 4th Century BC in which Alexander the Great expanded his empire westward instead of eastward. She asked, “What would have been the results for Rome if she had been engaged in war with Alexander?” However, in the English language, the first known complete alternate history was Nathaniel Hawthorne’s short story “P.’s Correspondence”, published in 1845. It narrates the tale of a man who is considered “a madman” due to his experience of a different 1845, a reality in which long-dead famous people such as the poets Burns, Byron, Shelley, and Keats, the actor Edmund Kean are still alive. The Man in the High Castle by Philip K. Dick has the United States losing World War II and is ruled jointly by Japan and Nazi Germany. This book won the 1963 Hugo award and established Dick’s literary career.
According to writer and editor Steven H. Silver, alternate history requires three things:
1) the story must have a point of divergence from the history of our world prior to the time at which the author is writing
2) a change that would alter history as it is known
3) an examination of the ramifications of that change.
This type of writing has its pros and cons. A writer can draw from actual history for plot lines and characters. A time line has already been established and therefore, the writer wouldn’t have to develop one from scratch. Thus, also eliminating any difficulties in naming characters or choosing a setting. However, this can also be a con. Setting a story in certain time and place in history requires research. The character and plot being added in to the historical timeline must provide a logical fit.