French and British leaders met Friday at a moment of European splintering to remember the centenary of the Battle of the Somme and pay tribute to their soldiers who shared trenches.
Beginning on July 1, 1916, and dragging on more than four months, the battle was one of the largest of World War I. The conflict prompted a political shift that partly laid the foundations for another war less than three decades later, leading European nations to ultimately pledge alliance with one another instead of emnity.
In an unprecedented challenge to that post-war consensus, Britain voted last week to leave the European Union and sever ties with the most prominent institution of regional cooperation.
Members of the British royal family attended Friday.
French President Francois Hollande and British Prime Minister David Cameron were present, having made last-minute decisions to attend the ceremony in a signal their shared desire to maintain their countries' continued bond.
French and British forces fought together during the Battle of the Somme to resist the advance of Germany. The battle, the bloodiest in British history, left more than 1 million dead, wounded or missing.
Britain held a two-minute silence Friday morning to mark the centenary, while leaders gathered for a midday ceremony at a memorial in Thiepval in northern France. Prince Charles and Camilla, the duchess of Cornwall, were joined by Prince William, Catherine, the duchess of Cambridge, and Prince Harry for the ceremony.
German ex-president Horst Koehler and Irish President Michael Higgens took part in laying wreaths at a cross at the Thiepval memorial to more than 72,000 British Empire soldiers who died with no known graves. Scottish leader Nicola Sturgeon was in attendance.
The ceremony began with canon shots, followed by excerpts of war-era texts, read by service men and women as well as public figures, including Hollande, Cameron, Prince Charles and football player Sol Campbell. Letters from the front, poems by soldiers lost to battle and eyewitness accounts from medical personnel were among the readings.
Tenor Samuel Boden sang the hymn Abide with Me and the BBC symphony orchestra played Banks of Green Willow. British and French flowers of remembrance, poppies and cornflowers, were pinned to leaders' lapels. French and British schoolchildren laid wreaths at grave markers.
Cameron and Hollande did not make public statements during the ceremony. After a working lunch with the British premier, Hollande told journalists that Britain's choice to leave the European Union was decisive.
"Being in the European Union has advantages," Hollande was quoted by the AFP news agency as saying. "And that's what I think many Britons are being to understand, ... but the decision was taken - it cannot be postponed or annulled. The consequences must be drawn."
Hollande has repeatedly said that France's relationship with Britain will continue, but he has warned that it will not be possible for London to continue to enjoy the advantages of EU membership without accompanying responsibilities. This week in Brussels, Hollande said border treaties between the two countries would not be affected by Britain's exit.
Cameron did not make a statement, but Downing Street said that the two leaders had discussed continued cooperation on security matters. It said the prime minister expressed his view that Britain would seek the "closest possible" relations with the EU.
The Press Association reported that the wreath laid by Cameron at Thiepval memorial carried a note reading, "Yours was the most horrific slaughter of a generation. We stand in awe of your sacrifice, determined that your legacy of liberty will live on forever."