Prince Charles has paid tribute to those who fought for a "free Europe" in the 1944 D-Day landings in Normandy.
The Prince of Wales said the soldiers' bravery and sacrifice led to "stunning victories" and "peace, prosperity and better common understanding".
But he added: "We must never forget that these victories did not come without enormous cost."
The Prince's message marks the 60th anniversary of D-Day. He will attend commemorations in Normandy this weekend.
The Queen, Prime Minister Tony Blair, US President George Bush, French President Jacques Chirac and Russian premier Vladimir Putin will also be present.
On 6 June 1944 some 5,000 allied vessels headed to the shores of occupied France in the biggest seaborne operation in history.
Of three million men who fought in the subsequent battle around 250,000 were killed.
Prince Charles said: "The stunning victories achieved on the first day secured the vital foothold,
and in their success lay the liberation of France and, from there, the rest of North West Europe.
"Sixty years later, with old adversaries now reconciled, together enjoying peace, prosperity and better common understanding, it is hard to imagine the devastation wrought on France and the immense struggle that took place there to deliver it from the yoke of organised barbarism under which it had suffered.
"But the free Europe we know today could not exist, had not the tide of war been turned in Normandy in 1944."
Prince Charles said it was important to remember that many of those who died had been the same age as his sons, Princes William and Harry.
He said: "It is only that way we can begin to understand the real extent of the sacrifice that was made and of the heartrending suffering of the families in this country, and in France, whose loved ones were torn away from them in the course of doing their duty.
"And they are still doing it today on our behalf, so we owe these men and women our profound respect and everlasting prayers of gratitude."