A Tornado roared overhead as a memorial was unveiled to those who took to the skies for their country almost a century ago.

Narborough Aerodrome was Britain's biggest air base during the First World War. But today almost all that remains is a track leading out across the fields.

Yesterday a guard of honour from nearby RAF Marham snapped to attention as Sir Michael Beetham, former Marshall of the RAF and one of the last surviving Lancaster bomber pilots, arrived.

'In 1915 and airfield was built here,' he said. 'Pilots and observers were being trained for the Western Front and casualties were high.

'Forty-one people were killed and a number of them are buried in All Saints Church in narborough.

'It's very important that what was at Narborough is remembered for history.'

Pilots from the Royal Naval Air Service, Royal Flying Corps and American squadrons trained over Norfolk before being sent to the Western Front.

Casualties were high among those who flew their flimsy by-planes over enemy lines, to act as artillery spotters.

Those on board the wood and canvas aircraft didn't even wear parachutes. And many perished on training flights, with engine failure the commonest cause.

The memorial stands off Chalk Lane - where the guard house at the entrance to Narborough Aerodrome would have stood - opposite the lane which leads to the main gate of RAF Marham.

Almost nothing remains today of 1,000 acres of runways and hangars.

The memorial was decicated by Canon Stuart Nairn, Rector of the Nar Valley.

'Their actions and their sacrifice are their remembrance,' he said. 'We come to dedicate this memorial so there may be a place on earth dedicated to their memory.'

Dignitaries including Georgina Holloway, High Sheriff of Norfolk, and Shirley Matthews, Mayor of Swaffham, joined parish councillors and veterans.

Wreaths were laid before a Tornado thundered overhead. They included a tribute from Col Christopher Kulas, commanding officer at RAF Mildenhall.

Some of the first American airmen to serve in Britain trained at Narborough.