Jurgen "Iron-Hand" Hauptmann was a high ranking member of the Estonian military who became an ally of HYDRA during World War II.
After escaping Germany to avoid capture during the war's end, Hauptmann was later approached by Baron Zemo and Arnim Zola to continue HYDRA's work despite its downfall, and also partially to cash in a favor owed to Helmut's father. He would later pass away many years later in the late 80's due to his old age, not living long enough to see the organization rise up again in the modern era thanks to the machinations of fellow war survivors Baron Wolfgang von Strucker and Werner Reinhardt.