The Black Martians are on of the eldest races of Martian humanoids. They themselves claim to be the first sentient species on the planet, calling themselves First Born. They are distinguished from the rest through the color of their skin, the color of "polished ebony". They have settled themselves around the southern polar regions of Mars. They have a thriving population estimated to include about 200,000 people.

Convinced of their own racial superiority, the Black Martians wage wars, and raids against the lesser races. Captives are kept as slaves. Both to serve as a labor force for the First Born society, or as amusement in gladiator combats, orgies, and (reputedly) torture fests. They have no taboo against eating captives, though the practice is far from universal. They have created the dominant religion on Mars, that of the living goddess Issus. Though their priesthood and the goddess herself are corrupt beyond redemption.