The event involved a Red Arrows flight in formation with four Typhoon aircraft along the River Thames to the London Eye to mark the actual birthday.

It started south of London City Airport, passing the O2, Canary Wharf, Tower Bridge and Tate Modern before flying over the London Eye.

The fly-past could be heard in 10 Downing Street, where Prime Minister Gordon Brown broke off from his regular monthly press conference to pay tribute to the work of the RAF, as well as the Territorial Army, which mark is marking its 100th anniversary.

As his voice came close to being drowned out by the sound of the jet engines, a smiling Mr Brown told reporters: "That is, by the way, the Red Arrows. This is to commemorate the 90th anniversary of the RAF and we are also celebrating the 100th anniversary of the Territorial Army.

"We congratulate both the RAF and the TA on their huge achievements for the country."

The RAF was created when the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS) merged on April 1, 1918.

That day marked the creation of a third force as the RFC had belonged to the Army and the RNAS was under Naval control.

The start of the Royal Air Force's 90th anniversary celebrations was marked on Monday as a Chinook helicopter delivered badges to 25 veterans.

The servicemen, who between them flew in all major conflicts since the Second World War, were given their badges by Veterans Minister Derek Twigg.