John was educated in Shrewsbury and Queen's College, Belfast, qualifying M.B., B.Ch., B.A.0. (R.U.I.) in 1900. He was employed as a civil surgeon, then on 29th January 1901 took up a commission within the Medical Services at the rank Lieutenant. He saw active service in the South African war during 1901 and 1902, being awarded the Queen’s SOuth African Medal & 4 clasps. From 1903 to 1905 he served in Halifax, Nova Scotia, during which time he gained promotion to the rank of Captain on 29th January 1904. From 1908 to 1913 he was stationed in India, being promoted to the rank of Major on 29th January 1913. After war was declared, John formed No 1 Base Depot of Medical Stores at Woolwich, becoming the Commanding Officer. The unit was mobilized on the 18th August 1914, then sailed from Southampton to Havre, resulting in John entering the war in France ob 21st August 1914. On 7th October 1919 he was awarded the Portuguese Military Order of Avis 3rd class, and on 17th March 1920 he was awarded the French Order de l’Etoile Noire (Officer) After the war he returned to India, serving there from 1920 to 1923. On 3rd March 1923 he retired with pay, then on 11th August 1928 ceased to be on the Roll of Officers.