Walter was educated at St. Thomas's Hospital, where he took the diplomas of M.R.C.S. (Eng), L.R.C.P (Lond) on 11th May 1900. He gained a commission in the Medical Services, at the rank of Lieutenant on 21st June 1900, then served in India from 1901-1906 - during which time he was promoted to captain on 21st June 1903, and became a specialist in Bacteriology in 1908. Between 1910 and 1912, Walter served in Egypt, being seconded to the Egyptian Army. On 21st December 1911 he was promoted again to Major. Walter entered the war in France on 21st August 1914. He was taken prisoner during the retreat from Mons, and was held, along with 13 other British medical officers at Torgau. On 10th February 1915, he along with Captains Priestley, Field, Sutcliffe, Vidal, and Lieutenant Lauder, volunteered to go to Wittenberg camp, Saxony to provide medical care to prisoners of war. On his journey there he learnt that the camp was riddled with typhus. Walter was said to have “broken down” after seeing the conditions of the prisoners and the camp. He caught typhoid on 7th March 1915. His services in the POW camp was brought to notice on 10th January 1919. He was the son of Lewis I and Isabella C Fry.