Thomas von Stockhausen was the Imperial Admiral placed in command of Iserlohn Fortress, sometime after the Fourth Battle of Tiamat. He shared command of Iserlohn with admiral Hans Dietrich von Seeckt, who commanded Iserlohn's defense fleet, the both of them having replaced admiral Gregor von Muckenberger at his retirement.
Admiral Stockhausen holds the dubious honor of being in command of the fortress when it was captured. Stockhausen allowed the Rosen Ritter, led by Walter von Schenkopp, into Iserlohn's command center. Schenkopp took Stockhausen hostage. Stockhausen's seccond in command, Commander Rahkan, told Schenkopp his actions were useless: Stockhausen was a loyal Imperial officer, and would gladly sacrifice his life for the Empire. Stockhausen, however, surrendered and ordered Rahkan to stand down, allowing the Rosen Ritter to sieze control of the command center and Yang Wenli to capture the fortress.