Foundation series
Asimov wrote hard science fiction. Along with Robert A. Heinlein and Arthur C. Clarke, Asimov was considered one of the "Big Three" science fiction writers during his lifetime. Asimov's most famous work is the "Foundation" series, the first three books of which won the one-time Hugo Award for "Best All-Time Series" in 1966. His other major series are the "Galactic Empire" series and the Robot series. The Galactic Empire novels are set in the much earlier history of the same fictional universe as the Foundation series. Later, with "Foundation and Earth" (1986), he linked this distant future to the Robot stories, creating a unified "future history" for his stories much like those pioneered by Robert A. Heinlein and previously produced by Cordwainer Smith and Poul Anderson. He also wrote over 380 short stories, including the social science fiction novelette "Nightfall," which in 1964 was voted the best short science fiction story of all time by the Science Fiction Writers of America. Asimov wrote the "Lucky Starr" series of juvenile science-fiction novels using the pen name Paul French.