Stanley Elder Humphreys was born in Ballarat and educated at Ballarat College before studying medicine at the University of Melbourne. At the age of 26, while serving a medical internship in London, he enlisted as a Lieutenant with the Royal Army Medical Corps on April 24th 1915. Promoted to Captain in May 1916, he served in France and England with Scottish troops before being discharged in August 1916 following an illness earlier that year.

Source: "in the Footsteps of Pompey" by James Affleck