Thomas William Brain originally trained as a bootmaker, but in 1914, with his wife Effie and mother, Maria Constance Brain, nee Murnane, was working as a hotel keeper in the Western District. On his enlistment he gave his address as 95 Victoria Parade, East Melbourne, btu he may well have just come down in order to enlist. He signedcup on 28 June, 1916, and was sent to Ballarat for training, then embarked from Melbourne on HMAT Nestor A71 for England, arriving at Plymouth on 16 November, 1916. By then his record had a black mark - he was charged with using obscene language towards an officer on 29 October and sentenced to 14 days' Field Patrol and loss of wages. As a result, he did not leave for France until February 24, 1917, leaving England on the SS Golden Eagle from Folkestone, and marching in to Etaples on 26 February.

He served exactly two months with his battalion, before being diagnosed with Gonorrhea and placed in the 57th General Hospital at Etaples. He was discharged to duty, joining his battalion on 5 May, but the next day was admitted with haemorrhoids to the 36th General Hospital, before being sent back to England, embarking on SS Cambria on 19 May, where he was admitted to the London General Hospital.    

Following his release from hospital, he was sent on furlough to Perham Downs, then returned to Australia on 5 September, 1917. He was discharged from the AIF at Melbourne on 10 December that year. In 1919, he was living at 422 Lydiard St., Ballarat, with his wife Effie and gave his occupation as 'soldier'. By 1936, he was single, living in Port Melbourne and working as a labourer. He was still in Port Melbourne in 1949, when he would have been 69.