By 1930 the Royal Air Force had expanded and newer, faster aircraft were in service. There were major establishments in Egypt and at home, and the service deployed squadrons in India, Palestine, Iraq and Singapore. The empire's air routes were opening up and long-distance flights by landplane and flying boat were becoming almost routine.

Amid this period of rapid development, operations continued against warring tribes on the North-West Frontier of India, against Arabs in southern Iraq and Kurds in the north of the country, and against Arabs and Jews in Palestine. The service expanded in the early years of the decade and monoplane designs for fighters and bombers were on the drawing board. Through much of this period the assumption was still that the bomber would reign supreme and that growth of the offensive squadrons was the priority.

In 1935 Italy invaded Abyssinia, resulting in the transfer of several squadrons from the United Kingdom and the deployment of aircraft carriers and other capital ships of the Royal Navy. By this time plans for expansion were in hand, and from 1937 the first Hurricane squadron was formed. This was soon followed by the first Spitfire squadron. By the outbreak of war in September 1939 the RAF was a mature and capable force. Royal Air Force Operations 1930 to 1939: Preparing for War charts this process in fascinating detail alongside a magnificent collection of contemporary photographs.