The Royal Air Force Ensign is the official flag which is used to represent the Royal Air Force. The Ensign has a field of air force blue with the Union Flag in the canton and the Royal Air Force roundel in the middle of the fly.
The RAF Ensign was introduced in 1921 after some opposition from senior members of the Royal Navy. Various nations' air force ensigns have been based upon the RAF Ensign. Currently it is flown from the flagstaff of every Royal Air Force station during daylight hours and permanently displayed on the Cenotaph in London.