Complex sentence: After the war he studied at Worcester College, Oxford for a year, but ultimately decided to resume a military career when he was offered a place at the Royal Military College, Sandhurst, althouh he quickly decided it was not for him.
Split into simpler sentences: After the war he studied at Worcester College, Oxford for a year. He decided to resume a military career when he was offered a place at the Royal Military College, Sandhurst, but he quickly decided it was not for him.