Lyon Sprague de Camp who has died aged 92, was one of the last survivors of the golden age of science fiction and fantasy. His first story was published in America in Astounding Stories (better known as Astounding Science Fiction) magazine in 1937, shortly before its famous editor John W Campbell took it over. He retained his association with Campbell and Astounding for many decades.
But it was the launch in 1939 of a shorter-lived sister magazine, Unknown, that opened the doors for de Camp. Here he was able to explore the fantasy genre for which he is better known though there was often a blurring of boundaries between the two in his work. His SF was fantastical, while his fantasy was, if not scientific, at least rational.
In what is generally considered his best SF novel, Lest Darkness Fall (1941), an American accidental time traveller goes back to the late Roman Empire well researched and beautifully realised - and attempts to introduce printing and other modern technology to stop the Empire's collapse; he is frustrated by his lack of specific knowledge and tools.
In his best fantasy novel, The Incomplete Enchanter (1940), written with Fletcher Pratt, the protagonist discovers a mental and mathematical means of travelling to other worlds of probability. Aiming for the world of Irish mythology, he ends up instead entangled in Norse myth, and in a later trip, in the land of Spenser's Faerie Queene. He too is frustrated; his gun won't work in this alternate reality, and his copy of the Boy Scout Handbook becomes unreadable.
The Incomplete Enchanter has reappeared with its sequels under a bewildering variety of similar titles; it was reissued in Britain just last month as The Compleat Enchanter in Millennium's Fantasy Masterworks series. Like much of de Camp's work, it is something of a light-hearted romp; in many ways he laid the groundwork for comic fantasists such as Terry Pratchett and Tom Holt.
In a 1947 essay, Humour in Science Fiction, de Camp wrote, "The mere fact that a narrative depends for its appeal upon humour doesn't excuse the author from writing a good story. The yarn still needs structure, characterisation, movement, narrative hook, build-up, climax, and all the rest." This is a lesson that many of today's lesser humorous fantasists could do with learning. De Camp also completed several of Robert E Howard's Conan the Barbarian novels, and wrote a biography of the writer; his biography of HP Lovecraft was well regarded.
Born in New York City, de Camp was a trained engineer. He studied aeronautical engineering at California Institute of Technology, taking a masters degree in 1933. He went on to work in patents, and then in defence engineering. His first (co-written) book was Inventions and Their Management (1937), and over the years he wrote The Evolution of Naval Weapons (1947), The Heroic Age of American Invention (1961), The Story of Science in America (1967), and other non-fiction books. During the second world war he was an engineer at the Philadelphia Naval Yard alongside fellow SF luminaries, Isaac Asimov and Robert A Heinlein.
For most of his life, though, he was a writer and editor, and clearly loved his work, producing more than 40 novels and 60 other books, including short story collections, books of verse, anthologies, and much non-fiction. He once wrote, "I esteem my readers, since they enable me to live without working. I merely do what I like to do - write - and people are rash enough to pay me for doing it."
Much of his work was co-written with his wife, Catherine; they married in 1939, and she died last April. Perhaps their best-known collaboration was Ancient Ruins and Archaeology (1964), published in Britain under the title Citadels of Mystery. This takes a serious look at some of the most famous legendary and mythological sites, including Stonehenge, Troy and Easter Island.
However eclectic his work, L Sprague de Camp was best known for his fantasy and science fiction. In a rather backhanded compliment, SF writer and historian Brian W Aldiss once wrote that de Camp "never produces masterpieces, but is nonetheless rarely dull". De Camp may not have been one of the very top-rank SF and fantasy writers, but both genres would have been much poorer without him, and this was recognised by his peers with a Grand Master Award from the Science Fiction and Fantasy Writers of America, and by his fans with a World Fantasy Convention Award.
He is survived by two sons.