Amhor is a red Martian kingdom approximately seven hundred miles north of Morbus, and the long-time enemy of the kingdom of Duhor. After Duhor's princess, Valla Dia, rejected the advances of the Amhorian prince Jal Had, he led an invasion of her homeland in an attempt to capture her and force her to marry him. After the kingdom was sacked, however, Valla Dia disguised herself as a homely slave, and as a result, she was sold to Ras Thavas in distant Toonol, who transferred her consciousness into the body of the hideous old queen Xaxa of Phundahl, whose own consciousness was transferred into Valla Dia's considerably younger body.
Amhor is seen again when Vor Daj, whose brain has been transfered to the body of the Hormad Tor-Dur-Bar, is captured in the Toonolian Marshes and imprisoned in the zoo of prince Jal Had.