Cyril Thomas Teer Hagen was the eldest son of Thomas Teer Hagen and his wife, Emma Frances, nee Fisher.  He was born in Nerrandera, New South Wales c.1890.  His father was a bootmaker who later in life was described as a ‘gold mining expert’. When he enlisted at Melbourne on 29 September 1916 Cyril gave his occupation as civil servant.  His address, where he lived with his wife, Maud, was Rosebank, 200 Clarendon Street, East Melbourne, which at the time was a boarding house.

Cyril was appointed to 2nd Divisional Signal Company, 19th Reinforcements and sent to Seymour for training.  He embarked on 23 December 1916 aboard RMS Orontes, arriving at Plymouth 17 February 1917.  Initially he was sent to Details Camp at Perham Downs, followed by a stint at Shefford, and then was sent to France where he was taken on strength of his unit on 15 September 1917.

He was appointed Temp CQMS (Company Quartermaster Sergeant) 24 May 1919.  He was attached to staff officer at AASC (Australian Army Service Corps) No 2 Company in Belgium on 7 June 1919 and proceeded to Havre for return to England and AIF headquarters at Sutton Veny.  He left for return to Australia on 18 September 1919 and was discharged on 11 December 1919

By 1923 Cyril and his wife had moved to America and settled in San Francisco where by 1938 he was the manager of the Precision Electrotype Co