Thuvia, Maid of Mars (Mars series #4 (Del Rey Books Numbered))

This fourth Martian novel turns to the next generation of Barsoomians. Cathoris, son of the Warlord of Mars, is one of two princes and a Jeddak who seek the hand of Thuvia of Ptarth. When she is kidnapped by Prince Astok, the entire planet faces a bloody war. Cathoris must follow in his father's footsteps, fighting savage beasts and phantom armies as he rescues Thuvia and saves Barsoom from destruction.