John was educated at a private and public school in Ware. He was a Sanitary Plumber and Fitter by trade and joined the St. John Ambulance Brigade in December 1912, which resulted in him being called to hospital work, serving at the Military Hospital, Colchester, and the Military Hospital, Lakenham, Norwich. He volunteered for foreign service in September 1915, entering the war in the Balkans on 11th July 1915. He saw service in Gallipoli - taking part in the evacuation there, and then went on to Mesopotamia from early in 1916. He was killed at a village about 80 miles above Bagdad, and was buried on the field of battle. Capt C O'Brien wrote: "During the past winter your son had done some very hard and good work. He was one of the best bearers in the Ambulance, and his loss is greatly felt by the officers and men." John was the youngest son of Charles Joseph Dewbury of Vine Cottage, Ware, Co. Herts. Divisional Superintendent, St. John Ambulance Brigade, Ware, Hon. Serving Brother of the Order of St. John of Jerusalem in England, by his wife, Susan Ann - youngest daughter of the late John Green of Ware.