The Royal Air Force came into existence on 1 April 1918 when the aviation branches of the Royal Navy and the British Army were merged to form an independent military force. The growing role of airpower in warfare, particularly in the Great War was the chief inspiration for this move.
The Commemorative Retail Booklet comprises four Machin Definitives flanked by the Hurricane and Lightning commemoratives. The self-adhesive stamps are printed in Gravure so that the RAF centenary stamps differ from those on the Miniature Sheet and Prestige Stamp Book.
The two BSSP covers each carry a single stamp, a complementary image and the appropriate handstamp.
