Joshua Clark is a Union Army Captain and an old enemy to John Carter.
Joshua Clark of Pennsylvania was a veteran of the American Civil War and fought on the side of the Union Army. He confronted John Carter in a battle in Manassa, Virginia in 1861 and after a duel, Clark was stabbed and defeated by Carter. He obliged the Confederate to finish him and give him a warrior's death, but John refused and left him for dead. Despite his grievous injuries, Clark survived and fought for the rest of the war, grinding the Confederacy under his booth. He fought for many other conflicts against the Indian Natives but he could never get over the one man who bested him in combat. He searched for Carter for many years, looking for retribution but he could never find him. One night, Clark was abducted by an alien race, the Kahori, sparing him at first because he was deemed a curiosity. Eventually Clark rose through the ranks up to the position of Warlord and conquered several other worlds. Years later, he invaded Barsoom after learning his nemesis Carter had became its Warlord, launching an all-out invasion against the planet.