Lyon Sprague de Camp (Nov. 27, 1907 - Nov. 6, 2000) wrote science-fiction, fantasy, historical fiction, and non-fiction. Aside from his ground-breaking alternate-history novels, Lest Darkness Fall (1939) and The Wheels of If (1940), de Camp is also known for his light fantasy collaborations with Fletcher Pratt (the Harold Shea stories) and his continuations of Robert E. Howard's Conan the Cimmerian with Lin Carter and Bjorn Nyberg. De Camp also wrote biographies of H. P. Lovecraft and Robert E. Howard.

Harry Turtledove wrote of de Camp: "I count him as my spiritual father. When I told him that in a letter in 1998, he replied that I gave him too much credit and myself not enough — again, utterly in character. Back in the days when I was trying to get my feet wet as a writer, I would say to my friends, "I want to be L. Sprague de Camp when I grow up." That was more than half a lifetime ago; I realize now, as I didn't then, how foolish I was. There was, and could be, only one of Sprague. Even so, in another sense I wasn't so far wrong after all. I could have picked a great many worse models, and very few better ones."