The Warlord of Mars by Edgar Rice Burroughs.

The Warlord of Mars by Edgar Rice Burroughs.  In this third installment of the adventures of John Carter on Mars, our hero labors under sentence of death (for having returned from the land of the dead) in a heroic struggle to recover the beautiful Dejah Thoris, Princess of Helium. He scours the planet from pole to pole, enduring imprisonment and torture, outwitting antagonists, reveling in carnage, accepting aid from unlikely sources, and dealing tactfully with women who love him despite his devotion to his wife. Having deprived an entire planet of its false religion, he offers in its place worldwide alliances and the promise of lasting peace.