Alfred Ernest Forbes was born in 1896 at Fitzroy, Victoria. Prior to enlisting in January 1916, Forbes was living in St Kilda working as a grocer, and had spent five years in the cadets and militia forces. He joined the 37th Battalion, trained as a signalman and was attached to the Headquarters section.

With the rest of his battalion, Forbes embarked from Melbourne on the troopship HMAT Persic on 3 June 1916. After brief stops at Albany and Cape Town, Forbes disembarked at Plymouth in England on 25 July. While travelling to the military camp at Lark Hill the train stopped at Exeter station and refreshments were provided by the mayor of the city himself, an event which Forbes records in his diary.

After further training, including in the Bustard Trenches around the Lark Hill camp, Forbes embarked for France on 22 November 1916. After serving on the Western Front for six months he was admitted to hospital with shell shock in May 1917. He spent approximately five months recovering before embarking for Australia on 31 October, and was discharged on 27 April 1918.

He married Alice Maude Porter in 1918 and returned to his pre-war occupation as a grocer in Prahran, Victoria. By the mid-1930s he had worked his way up to manager. Alfred Ernest Forbes died at Campbellfield, Victoria in 1946.