Gideon enlisted on 9th January 1903. He was 18 years and 10 months old and was a Tram Labourer by trade. He was service in the Barbados from 12th November 1904 to 20th December 1905, and then in Jamaica the following day. On 5th March 1908 he was stationed in Woolwich. On 8th January 1911 he was transferred to Army Reserve but he re-engaged on 8th November the same year. He was mobilized for war service on 6th August 1914 in Cork, then entered the war in France on 12th September 1914, as part of the Regimental Medical Officer's team for the 1st Bn. Leicestershire Regiment. On 12th January 1915 he transferred to serve with the 16th Field Ambulance. On 1st January 1916 he was sent to Base Details and transferred back to the UK with orders to report to the officer commanding the R.A.M.C. Depot in Aldershot for discharge on completion of service. He was discharged due to termination of engagement on 8th January 1916.