Born in Ballarat, William McCubbin was a single 19 year old farmer at the time of his enlistment in his birth town on the 20th of March 1916. His unit embarked from Melbourne, Victoria, on board HMAT A11 Ascanius on the 27th of May 1916.
On the 31st of December 1917, William was transferred to England due to a septic finger. On the 8th of April 1918, William left England for return to Australia, and was discharged as medically unfit on the 9th of October 1918.
Tree No. 1231