Complex sentence: After the war, De La Penne continued in the Italian Navy, being promoted to "Capitano di Fregata" (Commander) in 1950 and "Capitano di Vascello" (Captain) in 1954.
Split into simpler sentences: After the war, De La Penne stayed in the Italian Navy. He was promoted to "Capitano di Fregata" (Commander) in 1950 and "Capitano di Vascello" (Captain) in 1954.