Seventy-five years after the wooded hills of the Ardennes saw the bloody turning point of World War II, US and European leaders gathered Monday to pay their respects.
A king, a grand duke, two presidents, two prime ministers and a US defence chief celebrate those who died defending Belgium and Luxembourg.
The Battle of the Bulge was the last German offensive of World War II, and the Siege of Bastogne was the scene of a heroic defence by American paratroopers that has been celebrated in film and literature.
Veterans, historians and military enthusiasts marked the now legendary close-quarters battle on a snowbound wooded plateau with a spectacular series of weekend re-enactments ahead of Monday's ceremonies.
Bastogne's rescue in late December 1944 by General George "Old Blood and Guts" Patton helped seal his reputation as an American military giant.
But the out-gunned paratroopers of the 101st Airborne -- who held the pocket for a week against advancing German armour -- also claim a share of the glory.
"This is a great trip. It's professional for me on one hand, and personal on the other because I served in the 101 Airborne in combat," US Defense secretary Mark Esper said.
Esper was an officer on the "Screaming Eagles" in the 1991 Gulf War, winning medals for his part in the offensive into Iraq that helped evict Iraqi forces from Kuwait.
But on Monday he was to pay tribute to his comrades from an era that is passing from memory into history.
"Few Americans don't know about the Battle of the Bulge. It was the last major battle if you will of World War II," he told reporters who travelled with him from Washington.
"Much like Normandy that I attended this summer, this will probably be the last time when we can actually see some veterans of that campaign at a major point in time."
The Belgian town of Bastogne, close to the Luxembourg border in the Ardennes hills, is the focus of the commemoration, as it was of the fighting.
On December 16, 1944, German forces -- which had been falling back before the Allied advance from France since June's D-Day landings -- counter-attacked.
Their goal was to seize the port of Antwerp to deny it to Allied resupply ships, and five of their roads north converged on the small Belgian town.
By December 20, the battle-hardened but lightly armed US paratroopers were surrounded and a German Panzer general demanded their surrender.
"Nuts!" was the one-word reply from the US commander, and the ensuing week-long siege lasted until Patton's Third Army came to the rescue.
On Monday, Philippe King of the Belgians and Belgium's prime minister Sophie Wilmes will be joined at the Mardasson Memorial by Esper and Germany's President Frank-Walter Steinmeier.
Poland's President Andrzej Duda will also be there, along with senior envoys from Britain, Canada and France.
In the afternoon, the convoy will cross the border to the Luxembourg Military Cemetery and Memorial in Hamm, Patton's last resting place.
The general died in a road accident during the 1945 occupation of a defeated Germany, but was buried in the Ardennes with comrades from his famous victory.
His granddaughter Helen Patton has spent the days leading up to the memorial greeting veterans on battlefield visits.
There they will be received by Luxembourg's Grand Duke Henri and Prime Minister Xavier Bettel.
Mathieu Billa, historian director of the Bastogne War Museum, told AFP that the then 59-year-old Patton reached the summit of his glory when he relieved Bastogne.
The 18,000 encircled men had fought bravely against enormous odds, but risked being overrun.
The overall Battle of the Bulge would rage across the Ardennes for six weeks -- drawing in 600,000 American and 25,000 British troops against 400,000 Germans -- until the Allies prevailed in January 1945.
Between 15,000 and 20,000 German troops died, against between 10,000 and 19,000 Americans
And 3,000 Belgian civilians perished under artillery bombardments or in massacres carried out by the Waffen-SS in villages like Houffalize.
The Bastogne fighting has been recounted by veterans interviewed for the book and television series "Band of Brothers" and entered US military folklore.
But 75 years on, the number of former combatants and witnesses who can attend ceremonies is declining, and Belgium's War Heritage Institute has invited as many as they still can.
Bastogne, Belgium | AFP