A future history is a postulated history of the future that some science fiction authors construct as a common background for some of their stories. Sometimes the author publishes a timeline of events in the history, while other times the reader can reconstruct the order of the stories from information provided therein.

Perhaps the first detailed future history was that of Robert Heinlein, who originated the term in the sense described here. His collection The Man who Sold the Moon offers a vertical timeline labeled "FUTURE HISTORY 1951-2600 A.D." with stories and novels located appropriately, lives of significant characters marked with vertical bars, and commentary. His full future history is compiled in two volumes: The Past Through Tomorrow and Orphans of the Sky.

Other notable future histories:

• Larry Niven's Known Space series.
• H. Beam Piper's Terro-Human Future History.
• Isaac Asimov's robots, empire, and Foundation stories (the link between the robots stories and the others is a retcon).
• John Varley's Eight Worlds series.
• Iain M. Banks' The Culture.
• Frank Herbert's Dune.

A set of stories which share a backdrop but are not really concerned with the sequence of history in their universe are rarely considered future histories. For example, neither Lois McMaster Bujold's Vorkosigan Saga nor George R. R. Martin's 1970s short stories which share a backdrop are generally considered future histories.

Also, standalone stories which trace an arc of history are rarely considered future histories. For example, neither Walter M. Miller Jr.'s A Canticle for Leibowitz nor Olaf Stapledon's Last and First Men are generally considered future histories.

Unlike alternate history, where alternative outcomes are ascribed to past events; future history postulates certain outcomes to future events. One problem with future history science fiction is that it will date and be overtaken by real historical events (for instance, H. Beam Piper's future history, which included a nuclear war in 1973, and much of the future history of Star Trek). For this reason, some authors set their stories in an indefinite future, often in a society where the current calendar has been disrupted due to a societal collapse or undergone some form of distortion due to the impact of technology. In other cases, such as the Star Trek universe, the merging of the fictional history and the known history is done through extensive use of retroactive continuity. In yet other cases such as the Doctor Who series, much use is made of secret history in which the events which are to take place are largely secret and not known to the general public.

However, a number of hard science fiction writers extrapolate today's technology and events into the near future. Their stories need no fantastic technologies that have not yet been discovered but merely take the next step or two in foreseeable technological advancement and ask "What If?"

See also:

• Futurologist
• Post-apocalyptic science fiction
• World War III