Courtney joined the Royal Navy in May 1905 as a midshipman at Britannia Naval College.

[1] He fought in the First World War initially as Officer Commanding Killingholme Royal Naval Air Station.

Just before the end of World War I, Courtney was promoted to acting brigadier-general and sent France to command the 11th Brigade which was being established as a subordinate formation of the RAF's Independent Air Force.

[2] After the war he served as Officer Commanding, No 2 (Indian) Wing and then after a tour on the Directing Staff at the RAF Staff College, Andover, he was appointed deputy director of Operations and Intelligence at the Air Ministry.

[1] He became Air Member for Supply and Organisation in January 1940 and remained in that post throughout the remainder of the Second World War until he retired in 1945.