Barsoom is a fictional representation of the planet Mars created by American pulp fiction author Edgar Rice Burroughs. The first Barsoom tale was serialized as Under the Moons of Mars in 1912, and published as a novel as A Princess of Mars in 1917. Ten sequels followed over the next three decades, further extending his vision of Barsoom and adding other characters. The first five novels are in the public domain in U.S., and the entire series is free around the world on Project Gutenberg Australia, but the books are still under copyright in most of the rest of the world.