William Alex Halliday was born in Ballarat and was a Labourer by trade when he enlisted in the 22nd Battalion, 18th Reinforcement on 13 October 1916 at the age of 25. His unit embarked from Melbourne, Victoria, on board HMAT A20 Hororata on 23 November 1916 but en route he was hospitalised for two weeks at Durban, South Africa, suffering from pneumonia. He eventually disembarked at Plymouth on February 18th 1917 and had three months in England before transferring to the 22nd Battalion in France in mid-May. Apart from a septic foot, he was largely trouble free for the remainder of the war. He sailed from England in early July 1919 and disembarked at Melbourne on September 5th.
Tree No. 2564