Complex sentence: Post-war, Lyon served as Assistant Director of Quartering at the War Office, before finishing his career as Assistant Quarter Master General, retiring on half pay in 1927 with the honorary rank of Brigadier-General.
Split into simpler sentences: Post-war, Lyon served as Assistant Director of Quartering at the War Office. He finishing his Army career as Assistant Quarter Master General, retiring on half pay in 1927 with the honorary rank of Brigadier-General.