Complex sentence: He rose quickly through the ranks, reaching the rank of Major General by 1941, and then being appointed as "Chief of SS German Nationhood Staff", a position he held from November 1941 through his arrest by the Allied Forces in May 1945.
Split into simpler sentences: He rose quickly through the ranks, reaching the rank of Major General by 1941. Then he was appointed as "Chief of SS German Nationhood Staff", a position he held from November 1941 through his arrest by the Allied Forces in May 1945.