Travelling from across the world to monuments honouring soldiers who fell 100 years ago, victors and vanquished alike marked those sacrifices ahead of Armistice Day overnight and assessed alliances that have been redrawn dramatically since the dark days of World War I.
The leaders of former enemies France and Germany, in an intimate gesture that underscored their countries' current roles as guarantors of peace in Europe, held their heads together at the site north of Paris where the defeated Germans and the Allies signed the agreement that ended the 1914-18 war.
After Chancellor Angela Merkel briefly snuggled her head into the neck of French President Emmanuel Macron, the two went inside a replica of the train car where the armistice was reached and put their names in a guestbook. Macron then took Merkel's hand in his. "Our Europe has been at peace for 73 years. There is no precedent for it, and it is at peace because we willed it and first and foremost, because Germany and France wanted it," he said.
Merkel was equally convinced of the power their friendship exudes. "The will is there, and I say this for Germany with full conviction, to do everything to achieve a more peaceful order in the world even though we know we have very, very much work still ahead of us."
A flurry of Armistice-related diplomacy once again turned Paris, the jewel that Germany sought to take in 1914 but which the Allies successfully fought to defend, into the centre of global attention as dozens of world leaders arrived in the French capital. Merkel's appearance in Compiegne marked how her nation's bloodstained history with France has become a close alliance that drives the European Union.
In the four years of fighting, remembered for brutal trench warfare and the first use of gas, France, the British empire, Russia and the United States had the main armies opposing a German-led coalition that also included the Austro-Hungarian and Ottoman empires. Almost 10 million soldiers died. France lost 1.4 million and Germany 2 million.
World War II pitted both sides against each other once again in 1940.
Across the line that once marked the Western Front, leaders lauded the courage of soldiers who were killed during the unprecedented slaughter, before converging on Paris for a dinner.
Macron warned world leaders against taking peace for granted, saying "we will talk about this peace that our predecessors tried to construct 100 years ago but failed to preserve, because 20 years later a new war broke out".
The armistice entered into force on the 11th hour of the 11th day of the 11th month of 1918, and last night 69 world leaders commemorated the centennial of the event at the Tomb of the Unknown Soldier, underneath the Arc de Triomphe in central Paris.
Yesterday, Canadian Prime Minister Justin Trudeau went to Vimy Ridge, the battlefield in northern France where Canada found its sense of self when it defeated German opposition against the odds. Standing amid the white headstones against an ashen sky, Trudeau addressed the fallen, saying what Canada has achieved in the past century has been "a history built on your sacrifice. You stand for the values on which Canada was built".