Gerald Audrey Cadogan Cowper was born in England, probably Hertfordshire, in 1882, to Frank Cadogan Cowper and his wife Edith. He went to Preparatory School for two years in Hertfordshire, then on to Cranleigh College, Surrey, for five years. Cranleigh was reputed to have one of the best Cadet Corps in England. From here, Gerald Cadogan Cowper went in to the British Army and served ten months over 1900-1901  as a Trooper in the Boer War. In 1900, Lord Kitchener had sanctioned the raising of a regiment by Lord Tullibardine known as the Scottish Horse, recruited from Scotsmen, or men of Scottish descent in South Africa. It was composed  fo three squadrons and served in the field from 4 February, 1901. With peace declared in the Boer War, Gerald Cadogan Cowper became a Lieutenant of the 3rd Troop, A Squadron,  1st Regiment Scottish Horse, presumably back in England and later served as Lieutenant in charge of Irregular Horse in Mexico in 1909-10.

When World War 1 broke out, he was living at 151 Grey St., East Melbourne and working as a Real Estate agent. He married Linda Ida Schwarze, known as Ida, on 3 August, 1914, and had two children with her, Frank Cadogan Cowper (1915-1994)  and Gwendolyn Lois Cadogan Cowper. The couple divorced in 1930, with Ida claiming desertion. At this stage, Gerald Cadogan Cowper was living in Rukuhia, New Zealand. 

He must have enlisted almost as soon as war was declared and was immediately given the rank of Lieutenant on 28 August, 1914. By 18 October, he had the rank of Captain, was on strength with the newly formed 8th Battalion, 2nd Brigade. They embarked on 19 October, leaving Melbourne on board HMAT Benalla A24 , stopping briefly at Albany, Western Australia, before heading for Egypt. They were at Gaba Tepe (Anzac Cove) on 25 April, with the 2nd Brigade forming the second wave of troops. From Anzac Cove, they fought at Krithia on 28 April, with the loss of one-third of their Brigade, then again on 6 May, and 4 June. Gerald Cadogan Cowper had to be evacuated during the second battle of Krithis, suffering from a sprained ankle and a hernia. He was  first treated at the hospital ship, HS Newmarket, then transferred to St. Andrew's Hospital , Malta, disembarking from HS Ivernia  on 8 June, 1915. This effectively marked the end of any role in the fighting for him. He was placed on the Supernumerary List 'under the provisions of paragraph 20 of the Rules governing promotion'. 

On 14 January, 1916, he was appointed as a Flying Offcer with the Royal Flying Corps. A note on his record against this date says 'This officer has seen service in Flanders and Salonika with the Flying Corps'.  If he did, it must have been between June, 1915 and January 1916, but there is no other note of this service in his record. On  3 March, 1916, his record states that he is in Egypt, at Ismailia, with the No.14 Squadron Royal Flying Corps, but on 12 March, embarks for England from Malta and is admitted to Fishmongers' Hall (Officers' Hospital) London. He was operated on by Captain Fagge on 29 June and remained boarding there on 12 July. From here, he was given one month's leave, renewed twice further, and spent the months at the Royal Flying Corps base at Hurdon. Further leave was given and he moved to Carton Hall on 22 September, followed by six weeks light duties, which he again spent with the Royal Flying Corps. 

In April, 1918, a note was placed on his record: 'Examined b M.B. Unfit General Service. Fit H.S., but should not fly over 6,000 ft. Probably permanently unfit.' It was perhaps at this stage that his role became training other pilots, rather than flying with them. He served with the 30th Training Squadron and was given command of, first, the 8th Training Squadron AFC (25/10/1917 - 34/10/1917), then the 6th Training Squadron ( 1/3/1918 - 24/7/1918 ) and again, the 6th Training Squadron 26/8/1918). 

He spent some time from 1 July 1918, doing a course at the No. 1 School of Special Flying at Gosport and on 29 July, went overseas to France via Folkestone, returning the next day - was he perhaps delivering an aircraft?

Gerald Audrey Cadogan Cowper finished his military service in December 1918, returning to Australia  on board the  Takada, landing at Melbourne on 16  February, 1919.  He had resigned, so his appointment to the AIF had been terminated on 24 December, 1918, the same day he boarded the ship for home. In World War 11, he enlisted again, serving a Wing Commander in the R.A.A.F., stationed at Victor Harbour, South Australia, and was the Commanding Officer there. He would by then been sixty years of age.

He died, aged 82, at Preston, Victoria. having moved frequently during his working life.