Harold entered the war in France on the 18th August 1914, attached to the 15th Brigade. R.F.A. On 11th September 1915 he was serving with No 17 Casualty Clearing Station when he proceeded on leave for 5 days. He was awarded the Distinguished Conduct Medal, dated 11th January 1916. The citation reads: "For conspicuous bravery in collecting and bringing in, on his own initiative, officers and men of other regiments wounded. On another occasion he brought in without orders, two wounded officers to a dressing station, under heavy fire." He proceeded on leave on 3rd February 1917, returning on the 16th, and was mentioned in the unit war diary again on 15th May 1917 when he was given "300 francs for dry canteen".