A Princess of Mars is an Edgar Rice Burroughs science fiction novel.
It is a seminal example of the planetary romance genre, which became highly popular in the decades to follow, and also has some elements of Westerns. It is set on a dying Mars, informed by ideas popularized by astronomer Percival Lowell in the late 19th and early 20th centuries.
John Carter, a Confederate American Civil War veteran, goes prospecting in Arizona and, when set upon by Indians, is mysteriously transported to Mars, called "Barsoom" by its inhabitants. Carter finds that he has great strength on this planet, due to its lesser gravity. Carter soon falls in among the Tharks, a nomadic tribe of the planet's warlike, four-armed, green inhabitants. Thanks to his strength and combat abilities he rises in position in the tribe and earns the respect and eventually the friendship of Tars Tarkas, one of the Thark chiefs.
