Jack Slater (SN 1809) was born in Ballarat but enlisted In Melbourne on December 17th 1914. The unmarried, 22 year old sailor joined the 5th Battalion, 4th Reinforcement with which he embarked from Melbourne on board HMAT A18 Wiltshire in April 1915. On rejoining his unit at Lemnos after a bout of diarrhoea, he was promoted to Corporal and transferred to the 46th Battalion in March 1916, before being posted to France. In September, he was wounded in action for the first time and promoted to Sergeant. In February 1917, he was involved in the attack on Stormy Trench at Gueudecourt for which he received the Military Medal, the Commonwealth Gazette entry reading: 'This N.C.O. took part in the attack on STORMY TRENCH north east of GUEUDECOURT on the night of 11th/12th February, 1917, and took one prisoner. He had charge of a party detailed to construct one of the barricades, which he did in remarkably quick time and most effectively and later took charge of a wiring party in front of the new position. This N.C.O.'s work was conspicuous for its excellence and the coolness with which he carried out all whilst under heavy fire from the enemy. His example greatly encouraged his men to strenuous efforts on their part.'. A few weeks laterl, he suffered a severe gunshot wound to the left knee and, while recovering in England, attended officer training, resulting in his appointment as Second Lieutenant in June 1918. He spent much of the remainder of the war in France where he was promoted to full Lieutenant in September before transferring back to England in January 1919. He returned to Australia on board the Warwickshire in May 1919 and his commission was terminated on October 18th 1919.

His sister Muriel served in the Australian Army Nursing Service and is also honoured with a tree in the Avenue.