Complex sentence: He left the regiment in 1938, when he succeeded his father as Baron, but rejoined in 1939 with the outbreak of the Second World War, and served throughout the war, being twice wounded.
Split into simpler sentences: He left the regiment in 1938, when he succeeded his father as Baron, but rejoined in 1939 with the outbreak of the Second World War. Lopes served throughout the war, being twice wounded.