Our own Morgan Meis in The Smart Set:
His name was L. Ron Hubbard. This year, 2011, happens to be the 100th anniversary of his birth (on March 13, to be exact). By the mid-1950s, Hubbard was a legend. He'd written in every field and form imaginable. The pulps were his bread and butter. He churned out stories and novels. He wrote adventures and mysteries and thrillers and sci-fi. In 1934 he published, among other things, a mystery story called “Calling Squad Cars!”; a sea adventure featuring black pearls called “Pearl Pirate”; a Western called “Maybe Because—!”; an adventure story called “Yellow Loot” that includes a race along China's Great Wall; a detective story called “The Carnival of Death,” in which a U.S. Treasury agent solves murders at a carnival; and “Tooby,” a musical story about a tuba.
In 1940, Hubbard really seemed to hit his stride. He published a story called “Fear” in Unknown, one of the pulp magazines of the time. In the story, a professor publishes a paper debunking myths about the existence of devils and demons and is then hounded by said devils and demons. Ray Bradbury liked “Fear” a lot, calling it “a great scare.” Hubbard also wrote a sci-fi story called “Final Blackout.” It's the story of a lieutenant who comes to rule England after years of atomic warfare. Robert Heinlein (Starship Troopers, Stranger in a Strange Land) famously said the story was, “as perfect a piece of science fiction as has ever been written.”