Question: The British  socialite and artist Rosemary Pratt married this Royal Air Force officer, flying ace, courtier and author who served as what to King George VI?
Context: This is a list of flying aces in World War I from Canada.  A flying ace is a military aviator credited with shooting down five or more enemy aircraft during aerial combat.  Canadians served in the British flying services–the Royal Flying Corps, the Royal Naval Air Service, and the Royal Air Force, as Canada had no air arm until the formation of the Canadian Air Force on September 19, 1918. Air Marshal Sir Arthur "Mary" Coningham, {'1': ", '2': ", '3': ", '4': "} (19 January 1895 – presumably 30 January 1948) was a senior officer in the Royal Air Force.  During the First World War, he was at Gallipoli with the New Zealand Expeditionary Force, was discharged in New Zealand as medically unfit for active service, and journeyed to Britain at his own expense to join the Royal Flying Corps, where he became a flying ace.  Coningham was later a senior Royal Air Force commander during the Second World War, as Air Officer Commanding-in-Chief 2nd Tactical Air Force and subsequently the Air Officer Commanding-in-Chief Flying Training Command. Rosemary Pratt, Marchioness Camden (9 May 1921 – 27 February 2004), born Cecil Rosemary Pawle, was a British socialite and artist, best known as the first wife of Group Captain Peter Townsend, who later became romantically involved with Princess Margaret of the United Kingdom. Air Vice Marshal Harold Spencer Kerby, {'1': ", '2': ", '3': ", '4': "} (14 May 1893 – 8 June 1963) was Canadian-born air officer of the Royal Air Force.  He served in the Royal Naval Air Service during the First World War, where he became a flying ace with nine confirmed aerial victories, later transferring to the Royal Air Force, rising to command of British Air Forces in East Africa during the Second World War. Marshal of the Royal Air Force Charles Frederick Algernon Portal, 1st Viscount Portal of Hungerford, (21 May 1893 – 22 April 1971) was a senior Royal Air Force officer.  He served as a bomber pilot in the First World War, and rose to become first a flight commander and then a squadron commander, flying light bombers on the Western Front.  In the early stages of the Second World War he was commander-in-chief of Bomber Command.  He was an advocate of strategic area bombing against German industrial areas, and viewed it as a war winning strategy.  In October 1940 he was made Chief of the Air Staff, and remained in this post for the rest of the war.  During his time as Chief he continuously supported the strategic bombing offensive against Germany, and advocated the formation of the Pathfinder Force, critical to improving the destructive force of Bomber Command.  He fended off attempts by the Royal Navy to take command over RAF Coastal Command, and resisted attempts by the British Army to establish their own Army Air Arm.  Portal retired from the RAF following the end of the war.  He served as Controller of Production (Atomic Energy) at the Ministry of Supply for six years.  Portal was then made chairman of British Aluminium.  He was unsuccessful in fending off a hostile takeover of British Aluminum by Sir Ivan Stedeford's Tube Investments, in what was known as the "Aluminium War".  Afterward he served as chairman of the British Aircraft Corporation. Air Commodore Herbert Victor Rowley (24 October 1897 – 9 April 1966) was a British air officer of the Royal Air Force.  He was a World War I flying ace, credited with nine aerial victories while serving in the Royal Naval Air Service, but became a member of the Royal Air Force when the RNAS was consolidated into it.  Rowley remained in the RAF post-war, serving through World War II, until retiring in 1944. Group Captain Peter Wooldridge Townsend, (22 November 1914 – 19 June 1995) was a Royal Air Force officer, flying ace, courtier and author.  He was Equerry to King George VI from 1944 to 1952 and held the same position for Queen Elizabeth II from 1952 to 1953.  Townsend also had a romance with Princess Margaret. Air Commandant Dame Felicity Peake DBE (1 May 1913, Cheadle Hulme, Stockport, England – 2 November 2002) was the founding director of the UK's Women's Royal Air Force (WRAF).  She only started flying when her first husband took up the hobby in 1935, but in 1946 she would become the first director of the Women's Royal Air Force (WRAF).  She was Honorary ADC to King George VI from 1949 to 1950. Air Chief Marshal Sir James Milne Robb, {'1': ", '2': ", '3': ", '4': "} (26 January 1895 – 18 December 1968) was a senior Royal Air Force commander.  After early service in the First World War with the Northumberland Fusiliers, Robb joined the Royal Flying Corps and became a flying ace credited with seven aerial victories.  He was granted a permanent commission in the Royal Air Force in 1919 and commanded No. 30 Squadron RAF in the Iraqi revolt against the British.  In 1939, Robb travelled to Canada to help establish the Empire Air Training Scheme, a massive training program that provided the Royal Air Force with trained aircrew from Canada, Australia, New Zealand and Southern Rhodesia.  He commanded No. 2 Group RAF of RAF Bomber Command and No. 15 Group RAF of RAF Coastal Command. Air Vice-Marshal Geoffrey Arthur Henzell Pidcock {'1': ", '2': ", '3': ", '4': "} (6 November 1897 – 12 February 1976) was a senior officer of the British Royal Air Force.  After becoming a flying ace in the First World War, credited with six aerial victories, he remained in the newly created Royal Air Force after the war, serving as a senior officer during the Second World War and specializing in the development of armaments.  He retired in 1951.
Answer: Equerry