In World War II, he led Jagdgeschwader 51 up to the Battle of Britain and claimed a further six victories during World War II, in the process becoming one of only a few men to score victories and become an ace in both world wars.
During World War II, he commanded Jagdgeschwader 51 up to the Battle of Britain and claimed further victories, thereby becoming one of a small number who achieved this distinction in both world wars.