Admiral von Roeder was a high ranking member of the Nazis during World War II. By March of 1943, Adolf Hitler, furious about the continued survival of the Sub-Mariner, directly ordered von Roeder to eliminate the Atlantean monarch. To this end, the Admiral took on Oskar Kessler to assist him. Kessler, a brilliant scientist, had built massive robots to be used in warfare but lacked the faith of his superiors to build them. Liking the idea, von Roeder ordered Kessler to build an army. Manning one of the robots, the pair led their army into the ocean and threatened to kill an Atlantean boy if he did not reveal the location of Atlantis. When the boy told them the location of his home, they killed the boy anyway and staged an assault on the underwater kingdom. Namor came to the aid of his people, but despite his best efforts, Admiral von Roeder's attack only stopped when Namor was believed to have been crushed to death. Surviving, Namor followed them and pushed von Roeder and Kessler's robot down an underwater trench. The tremendous pressure caused their robot to be crushed, killing them. Namor then sent the severed head of the robot to the shores of Germany as a warning to the Nazis to not attack his home.