Beauchamp Proctor was South Africa's highest scoring ace during World War I. When the war began, he abandoned his engineering studies at the University of Cape Town to join the army. He served as a signaller with the Duke of Edinburgh's Own Rifles and saw action in German South-West Africa before his discharge from the army in August 1915. After completing his education, Beauchamp Proctor joined the Royal Flying Corps in March 1917 and was commissioned upon arriving in England.

On completion of his pilot training, he was assigned to 84 Squadron in late July and accompanied this unit to France in September 1917. An S.E.5a pilot, Beauchamp Proctor was just five feet two inches tall. His height made it necessary to raise the seat and modify the controls of the aircraft he flew. Despite these difficulties and a crash on March 11, 1918, Beauchamp Proctor claimed 54 victories that year and became the British Empire's highest scoring balloon buster.