Complex sentence: During the Second World War he was commissioned into the Oxfordshire and Buckinghamshire Light Infantry, rising to the rank of Captain, and spent the latter part of the war attached to the Army Operational Research Group for the Ministry of Supply.
Split into simpler sentences: During the Second World War he was commissioned into the Oxfordshire and Buckinghamshire Light Infantry, rising to the rank of captain. He spent the latter part of the war attached to the Army Operational Research Group for the Ministry of Supply.