 Medley had a painting in the International Surrealist Exhibition in London in 1936 and in 1937 Medley founded the Artists' International Association, AIA, which promoted socialist and avant-garde art.In 1938 he chaired a widely reported debate between Realists and Surrealists organized by the AIA.At the beginning of the Second World War Medley served as a Air Raid Precautions warden until he was offered a three-month commission by the War Artists' Advisory Committee, WAAC, to go to France to record troop landings for the British Expeditionary Force.