Harry enlisted into the R.A.M.C. on 27th May 1915. He was 28 years old, a Police Constable by trade employed by the West Sussex Constabulary, and living at 62 Ham Road, Worthing, Sussex at the time. He embarked on H.M.H.S. "Dover Castle" at Newport, with the 31st General Hospital, on 20th October 1915. Destination was Alexandria, where he disembarked on 1st January 1916. On various occasions from 31st March 1916 he was admitted into hospital, which resulted in him being posted to the Base Depot at Mesopotamia on on 22nd July. After several more admissions into hospital he was posted to Alexandria to serve on the hospital ship "Letitia". He arrived in Liverpool in February 1917, and was posted to Blackpool, where he joined the 3rd Training Battalion. In August 1917 he was again admitted into hospital. The diagnoses was suffering with bronchitis attributed by exposure on duty to damp and cold in the camps during ordinary military service in England. He was discharged "physically unfit” on 30th January 1918