History
These massive robots were created by Cpt. Oskar Kessler, a scientist that worked for Nazi Germany. No one took Kessler's invention seriously until March of 1943 when Admiral von Roeder decided to use the robots against to destroy the Sub-Mariner.
After Kessler built an army of these robots, he and von Roeder manned one of the robots as they led an assault on Namor's home of Atlantis in order to lure him out. Namor led his fellow Atlanteans against the army, destroying many of them. The attack stopped when where it was believed that Namor was killed in battle. Namor had survived, however, and pushed the robot piloted by Kessler and von Roeder into an underwater trench where the water pressure was high enough to crush the robot, killing the pair. Namor then sent the head of the wrecked robot back to Germany as a warning to the Nazis to stay away from Atlantis. The remaining robots were presumably destroyed by Namor and the Atlanteans.[1]