David Sydney Wanliss listed his home address in Flinders Street, Melbourne, Victoria, was married to Mrs. Jessie Wanliss and was previously a Lt. Colonel with the 52nd Infantry Battalion (previously a barrister) when he enlisted with the AIF at the age of 50. He assumed command of the 5th Battalion on June 8th 1915 , but according to a medical history report dated March 25th 1916 he suffered from convalescent enteric (typhoid fever) whilst at Gallipoli and was returned to England for recovery. On April 11th 1916 he returned to duty and re-joined his unit. He would again be examined by the medical board on February 21st 1918, whereupon it would be deemed he suffered from senility attributed to the previous typhoid fever. According to the notes in the report, Lt Col Wanliss realized this as well. He returned to Australia in July 1918 and received a medical discharge on July 20th 1918.