By Robert Hall
BBC News, Normandy
Harry Verlander was a radio operator in one of the Jedburgh teams
In the windswept sand dunes of Normandy, there are many reminders of the liberating forces, but the missions of one unit are far more difficult to trace.
It was a unit backed by the Supreme Allied Commander General Eisenhower, but recruited and trained in total secrecy.
Its teams were codenamed Jedburgh and each comprised three men from Britain, France and the United States.
Their mission was to parachute behind enemy lines, link up with local resistance groups and do all they could to prevent German reinforcements reaching Normandy.
Harry Verlander, from Kent, was a radio operator with Team Harold.
He says: "I suppose we were terrorists in a way.
"It depended which side you were on. I was one of the angry young men of the day - just worried that the war would be over before I could get involved."
Colonel William Pietsch is an American Jedburgh veteran. He was recruited by a founder member of the CIA and flown to England for training.
He says: "We were taught how to fire pistols and other weapons. They told us ways to break into properties and out of jail - everything we'd need to become bandits."
William Pietsch was recruited by a founder member of the CIA
Jedburgh team Quinine even included a member of European royalty. Prince Michel de Bourbon Parme says he was secretly selected whilst training with the US Army.
He says: "A man took me on to one side. He offered me the chance of travel and a return to my native France earlier than I had planned.
"I asked him how much they would pay me and he said 'Double'. I said 'I'm in.'"
One by one the Jedburgh teams took off from RAF Harrington in Northamptonshire. Today one of the old huts contains a small museum showing team members and their equipment.
Prince De Bourbon Parme remembers being given James Bond-esque gadgets, including pencils containing bullets, and says he was amazed at their ingenuity.
But one final instruction was less welcome.
The agents were among the few to know about the D-Day plans and capture was a huge risk.
So they were issued with cyanide capsules to use in any such event and Mr Piesch recalls the words of the mission commander.
Prince Michel de Bourbon Parme narrowly avoided being shot in the leg
"We were to pop the pill in our mouth, hold it in our cheek, and if it became necessary we were to bite down and take a deep breath - then goodbye Charlie," he said.
Hunted with dogs
Once in France, the Jedburghs began their task of disrupting transport and communications. Some blew up railway lines and bridges, others sabotaged German vehicles and telephone links.
There were many close shaves and near misses. Harry Verlander remembers German troops surrounding the wood in which he was hiding.
He says: "I climbed a tree to avoid them. There were soldiers with dogs, but we had learnt to evade them by urinating around the foot of the tree to throw them off the scent.
"In this case the troops gave up before they found us."
Prince De Bourbon Parme had a close encounter with an armed civilian.
"I heard a shot and turned round to see him with a pistol. The shot he fired passed through my pocket and my wallet, but missed my leg."
Mission commanders expected the Jedburghs to last just a few weeks, but fortunately for today's generation enough of them have survived to share their adventures.