Henry gained his medical education at King’s College Hospital, London, qualifying M.R.C.S., L.R.C.P. in 1882. He took up a commission within the Medical Services at the rank of Surgeon Captain on 2nd February 1884, then served in India, taking part in the expedition at Miranzai in 1891. On 2nd February 1896 he gained promotion to the rank of Surgeon Major. In 1901 he began to serve in Malta, being promoted to the rank of Lieutenant Colonel on 2nd February 1904 then on 27th March 1913 gained further promotion to the rank of Colonel. At the outbreak of war he was appointed as Assistant Director of Medical Services (1st Army) in the Central Force for defensive and offensive operations in the event of an invasion. Having reached retirement age he was retained on the active list from 21st July 1915. Henry died in Bournmouth, Hampshire. He was the son of Charles and Mary Cannon; and the husband of Louisa Monica (nee Coulthurst) - married on 23rd September 1896.