Sydney enlisted into the Royal Munster Fusiliers on 3rd March 1909. He was 20 years and 10 months old, and was a Clerk by trade. He transferred to the Royal Army Medical Corps on 12th May 1909. On 7th October 1913 he grained promotion to the rank of Corporal, and was appointed as a Clerk on 10th May 1914. He entered the war in France on 9th August 1914, as part of the team for the Deputy Director of Medical Services, Lines of Communication. He was discharged "no longer physically fit for war service" on 28th July 1915. He was the husband of Ethel May Wilson [nee Piggott].