Theophilus Martin Robin was born in South Yarra, Victoria, was single and a student living in Ballarat when he enlisted in the Field Artillery Brigade, Reinforcement 27 on 27 February 1917 at the age of 19. His unit embarked from Melbourne, Victoria, on board HMAT A15 Port Sydney on 9 November 1917. According to his records he completed his tour of duty without major incident, illness or injury, returning to Australia aboard the Marin and receiving his discharge orders on 11 October 1919.

His brother, Edgar De Jersey Robin (Tree No. 3717), enlisted with the same unit on the same day, embarking from Melbourne, Victoria, on board HMAT A15 Port Sydney on 9 November 1917.
Tree No. 3719