A Princess of Mars :

Captain John Carter of the Virginia Cavalry finds himself transported to Mars, and is immediately captured by the great and fierce Thark, Tars Tarkas. While still in captivity, he meets another captive, the raven-haired beauty, Dejah Thoris, grand-daughter of the ruler of Helium, the greatest city-state on all of Mars. John Carter sets about to deliver the beautiful Martian princess from the green men, and realizes that not only is she loved by all the red men of Mars, but she is also the one he loves.