Cap Badge - Royal Air Force The Royal Air Force (RAF) is the United Kingdom's aerial warfare force. Formed towards the end of the First World War on 1 April 1918,[2] it is the oldest independent air force in the world.Following victory over the Central Powers in 1918 the RAF emerged – at the time – the largest air force in the world.[4] Since its formation, the RAF has taken a significant role in British military history, in particular, playing a large part in the Second World War where it fought its most famous campaign, the Battle of Britain.