Complex sentence: He received a final promotion to Lieutenant Commander on 1 November 1943, and in July 1944 he was appointed as Chief of the 22nd U-boat Flotilla, a post he held until the end of the war.
Split into simpler sentences: He received a final promotion to Lieutenant Commander on 1 November 1943, and in July 1944 he was appointed as Chief of the 22. Unterseebootsflottille, a post he held until the end of the war.