 He served in France before being sent back to India in June 1916, from where he volunteered to served with the 7th Meerut Cavalry headquarters which went to Mesopotamia.He was promoted captain 17 August 1916; however this was later antedated to 1 September 1915.Metcalfe was mentioned in dispatches, reported in the "London Gazette" on 15 August 1917, and ten days later come notice that he had been awarded the Military Cross for distinguished service in Mesopotamia.