Percy Thomas Boucher Semmens was born in Ballarat, Victoria, was single and a Clerk when he enlisted with the General Service Reinforcements on 16 September 1918 at the age of 18. By this time the war was reaching a close and the armistice was signed, ending all conflict in Europe, two months later on 11 November 1918. As such his prospective unit was demobilised and he was discharged on 24 December 1918 before embarking overseas. Because of this he was not eligible for any medals.

His brother Herbert was killed in action in October 1917 and his sister Mary also served in the AIF and they are honoured with trees in the Avenue.