Complex sentence: Best served in the First World War as an intelligence officer on the British Army General List, was appointed Officer of the Order of the British Empire (OBE) and awarded the Belgian Croix de Guerre.
Split into simpler sentences: Best served in the First World War as an intelligence officer on the British Army General List. He was appointed Officer of the Order of the British Empire (OBE) and awarded the Belgian Croix de Guerre.