Warlord of Mars picks up where the previous book The Gods of Mars ended. John Carter's wife Dejah Thoris is imprisoned in The Temple of the Sun by the false goddess Issus. Accompanying Dejah Thoris in captivity is another princess, Thuvia of Ptarth. John Carter leads a rescue that will take him across the planet to the northern polar regions of Barsoom.
The story was first published as a four-part serial in late 1913 and early 1914. Later published as a complete novel in 1919.