Howard joined the British Army and was commissioned as a second lieutenant into the Coldstream Guards on 4 December 1942. He was given the service number 253901. He fought in the Italian Campaign, serving with the 3rd Battalion, Coldstream Guards, and came ashore during the landings at Salerno in September 1943. On 27 January 1944, during the First Battle of Monte Cassino, he was awarded the Military Cross (MC) "in recognition of gallant and distinguished services in Italy".