BRUSSELS — At a site where their countrymen once slaughtered each other with machine guns, artillery and poison gas, the leaders of Britain, France, Germany and other European nations commemorated the 100th anniversary of World War I and vowed Thursday to preserve peace on the continent.
About half a million people died in the arduous battles in the flat, often muddy killing grounds in and around the small Belgian city of Ypres in western Flanders between 1914-18, one of the sites that reflected the savagery of what became known as "The Great War."
German Chancellor Angela Merkel said holding a summit of the 28-nation European Union in the city that had to be rebuilt from scratch after World War I sends a powerful signal.
"I believe this shows us again in which good times we live today, because the European Union exists and because we have learned from history," Merkel said.
World War I was unprecedented in scope and savagery: It claimed some 14 million lives — 5 million civilians and 9 million soldiers — including sailors and airmen from 28 countries, and left at least 7 million troops permanently disabled.
"We should remember those who served and why they fought ... and we should recognize that the peace we have today is something we should cherish every day," said British Prime Minister David Cameron.
Commemorating the war's 1914 start, the leaders walked through Ypres to the sound of drums to attend the "Last Post," a bugle salute to the fallen performed each evening at Menin Gate. The gate has been erected as a memorial on the main road where British and Commonwealth soldiers marched off to the front, many to never return.
Summit chairman Herman Van Rompuy urged EU leaders to act as "the guardians of vigilance" to prevent a reoccurrence of the folly that once engulfed the continent.