Before his participation in the First World War, Tweed was one of those invited to the 19 December 1914 reception given by the High Commissioner to the captain and officers of H.M.S. New Zealand. He continued to study during the war, but was actively involved in military medical duties under the remit of the
New Zealand Medical Corps. In August 1917 he was a groomsman at the wedding of Lieutenant Ralph Fitzßoger B. Beetham, N.Z.M.R. where the congregation consisted chiefly of New Zealand nurses from the hospital at
Walton-on-Thames, the site of the major New Zealand hospital in the UK where Martin Tweed spent some time. On his return to New Zealand after the war, he returned to duty with the
New Zealand Expeditionary Force at the rank of Captain having already served in the UK, and on enlistment listed his mother as his next of kin, situated in Hobson Street, Wellington, New Zealand. His embarkation date was 28 February 1919 from Wellington, aboard the Marama, which was acting as the Hospital Ship. No. 2. During his time in the New Zealand Medical Corps. he rose to the rank of colonel and afterwards worked at
Wellington Hospital. He was the chief advisor to the Royal New Zealand Society for the Health of Women and Children. In 1972 he continued to be registered as living in
Heretaunga,
Wellington. He married Margaret Moss (née Elvery) on 8 July 1919 and had a two sons, William Moss Elvery Tweed (born 12 June 1925; died ??), who followed his fathers footsteps and studied at Guy's Hospital as a Gynaecologist, Phillipa Tweed (born 24 December 1922) and John Moore Tweed (born in Carterton on 27 September 1920; died 19 February 2013), and who went on himself to become a Physician and Rheumatologist, being awarded the MBE in 1991. ==References==