Mervyn Arthur Dunkin was born at Launceston, Tasmania on 6 June 1892 to parents John and Mary. A clerk by trade, he enlisted at Claremont on 10 January 1915 at the age of 22. Enlisting with the 12th Infantry Battalion, Dunkin was allocated the rank of private. On 19 April 1915, he departed Fremantle aboard HMAT Argyllshire. Whilst serving at Gallipoli with the 12th Infantry Battalion, Dunkin was promoted to the rank of lance corporal in December 1915. After the withdrawal from Gallipoli, he was transferred to the 52nd Infantry Battalion in March 1916. During the course of his service on the Western Front, Dunkin was promoted to the ranks of corporal in March 1916 and sergeant in April 1916.He was transferred to the 13th Infantry Battalion in October 1916 and was wounded in action in September 1917. After his convalescence, Dunkin was transferred to the 51st Infantry Battalion in May 1918. In 1919, after demobilizing in England, Mervyn Dunkin married and returned to Australia with his wife later that year.