This is a specially produced large (19 x 12 cm) glossy bookplate bearing the original signature of Air Chief Marshal Sir Arthur Sanders. 
Sanders was commissioned into the Northumberland Fusiliers in April 1916 but transferred to the Royal Flying Corps a few weeks later. He was a pilot on No 5 Squadron RFC and in May 1917 was wounded in a dogfight with German aircraft. As a result, he lost his arm but managed to land his aircraft.
During the Second World War, he first served on the staff of the RAF staff College where he was responsible for planning the first wartime course. In 1940 Sanders was appointed the Director of Ground Defence at the Air Ministry and his work was in part responsible for the establishment of the RAF Regiment in 1942. In late 1942 Sanders was appointed Assistant Chief of Staff (Air) at the Allied Force Headquarters and in January 1943 he took up post at Air Officer Administration at Bomber Command.