Barsoom is a fictional version of the planet Mars invented by author Edgar Rice Burroughs for a series of action adventure stories. In 1911, Burroughs, now better known as the creator of the character Tarzan, began his writing career with A Princess of Mars, a rousing tale of pulp adventure set on the planet. Several sequels followed, filling out his vision of Barsoom and developing it in more detail. A Princess of Mars was possibly the first fiction of the 20th century to feature a constructed language; although Barsoomian was not particularly developed, it did add verisimilitude to the narrative.
Richard A. Lupoff has advanced the theory that Burroughs was influenced in writing his Martian stories by Edwin Lester Arnold's earlier novel Lieutenant Gullivar Jones: His Vacation (1905), also known as Gullivar of Mars, though this has been disputed. Lupoff also speculates that Burroughs derived characteristics of his main protagonist John Carter from Phra, hero of Arnold's The Wonderful Adventures of Phra the Phoenician (1890).