The Royal International Air Tattoo (RIAT) is the world's largest military air show, held annually over the third weekend in July, usually at RAF Fairford in Gloucestershire, England in support of The Royal Air Force Charitable Trust. The show typically attracts a total of 150,000 to 160,000 spectators over the weekend.
The first Air Tattoo was staged at North Weald Airfield in Essex in 1971, with just over 100 aircraft taking part. The event was founded by Paul Bowen and Timothy Prince, who were CAA air traffic controllers, and Air Marshal Sir Denis Crowley-Milling.
From 1973 to 1983 it was held intermittently at RAF Greenham Common, initially under the title of the Royal Air Forces Association, South Eastern Area, Air Tattoo before moving to RAF Fairford in 1985. The show became the International Air Tattoo in 1976, and recognition of its unique status was granted by Queen Elizabeth II in 1996, when the current Royal International Air Tattoo title was adopted.
The show is a showcase for the world's military, and has become an important precursor to the Farnborough Airshow, which takes place a week after RIAT, every 'even' year. It allows the military aerospace industry to display and present its products outside the commercial pressures of the Farnborough show.
According to en.wikipedia