Bertram Bloomfield was 38 when he enlisted on 7 July, 1915. He was a married man, with a wife, Victoria May, and son, Eric. He gave his occupation at 'Typist', but in the previous years' Electoral Rolls, he had had other jobs, as a hotelkeeper at 243 Williams St., Melbourne in 1909 and as a brewer's assistant in 1914, while he was livng at 101 Powlett St., Melbourne. In 1915, he was still in East Melbourne at 1155 Hoddle St., but after he left for the war, his wife moved to a boarding house and gave her address as C% Mrs Spry, 27 Victoria Parade, Collingwood. 

Bertram Bloomfield trained at Broadmeadows and was promoted to Corporal on 14th July, 1915. He was placed in the new 31st Battalion, which combined recruits from Enoggera in NSW, with recruits from Melbourne. The two groups were combined in October, 1915 and the battalion sailed for Egypt on board HMAT Wandilla A62 on 9 November, 1915. After six months in Suez, they boarded HMT Manitou from Alexandria to France to join the British Expeditionary Force.

The 31st Battalion fought its first battle at Fromelles on 19 July, 1916, having entered the trenches only three days earlier. Fromelles was a bloodbath: the 31st Battalion suffered 572 casualties, over 50% of its strength. Bertram Bloomfield was one of the casualties. The 31st battalion played no major offensive role for the rest of the year.

Though his date of death is given as 21 July 1916 and his place of burial as Flerbaix (both in his file at National Archives of Australia), it is certain that he died in the Battle of Fromelles on the 19th & 20th July 1916 and that his place of burial is not known. He is commemorated on the Australian Memorial at Villers Brettoneux, France, on AWM Roll of Honour Card no. 145 and on Panel 118 in the Commemorative Area of the Australian War Memorial.

Victoria Bloomfield was given a pension of  two pounds, 1s and 6d per fortnight, with an additon one poound per fortnight for Eric.  She later moved to Kew, where she died on 25 August, 1932.