A Princess of Mars is an Edgar Rice Burroughs science fiction novel, the first of his famous Barsoom series. It is also Burroughs' first novel, predating his Tarzan stories. Full of swordplay and daring feats, the story is considered a classic example of 20th century pulp fiction.The Gods of Mars is another Edgar Rice Burroughs science fiction novel, the second of his Barsoom (Mars) series.