Harry Norman Turtledove is an American author who is best known for his work in the genres of alternate history, historical fiction, fantasy, science fiction, and mystery fiction. He is a student of history and completed his PhD in Byzantine history. His dissertation was on the period 565–582. He lives in Southern California.

Alternate history is a subgenre of speculative fiction in which one or more historical events have occurred but are resolved differently than in actual history. As conjecture based upon historical fact, alternate history stories propose What if? scenarios about crucial events in human history, and present outcomes very different from the historical record. Some alternate histories are considered a subgenre of science fiction, or historical fiction.