European royals and officials will mark the 200th anniversary of the Battle of Waterloo on Thursday with a call for reconciliation at the site where Napoleon Bonaparte's imperial ambitions ended in carnage.
A solemn memorial service will take place on the morning of June 18, 2015, marking the minute the first musket balls flew on the battlefield south of Brussels, followed by a huge sound-and-light show in the evening.
In Britain, heir to the throne Prince Charles and his wife Camilla will attend a special service at St Paul's Cathedral in London along with descendants of men who fought at Waterloo.
The British prince on Wednesday unveiled an official memorial at the battlefield to the allied forces that defeated Napoleon's French army, in a battle that left more than 10,000 dead and 35,000 wounded.
Belgium, whose geography for several centuries made it the scene of conflict between European powers, wants to "use this occasion to send a message of reconciliation and unity," said an official in the cabinet of Belgian Prime Minister Charles Michel.
The Battle of Waterloo remains a sticky subject in Europe, particularly France, and its bicentenary comes as modern Europe grapples with a debt crisis in Greece and a stand-off with Russia over the conflict in Ukraine.
A total of 200,000 spectators are expected to make their way to Waterloo over three days of memorial events, starting with Thursday's commemorative service and ending with two days of battle re-enactments on Friday and Saturday.
Belgium's King Philippe will lead a ceremony at 0900 GMT at the foot of the famous Lion's Mound monument erected in 1826 at the battlefield site to pay tribute to those who died.
The Grand-Duke of Luxembourg and the Duke of Kent, the cousin of Britain's Queen Elizabeth II, will also be there, along with Frans Timmermans, the first vice-president of the European Commission.
But French President Francois Hollande and German Chancellor Angela Merkel will instead be represented by their countries' ambassadors, reflecting how sensitive the battle remains even two centuries later.
"It's a shame," said Charles Bonaparte, a descendant of Napoleon's brother Jerome. "There is no reason to be ashamed of his history. Waterloo was the beginning of a legend, Napoleon is known all around the world."
In a symbol of reconciliation, Charles Bonaparte on Wednesday shook hands with the Duke of Wellington, descended from the famous British general of the same name, and Prince Nikolaus Bluecher von Wahlstatt, whose ancestor led the Prussians.
The battle was a pivotal moment in European history, when around 93,000 French troops led by Napoleon faced off against 125,000 British, German and Belgian-Dutch forces commanded by the Duke of Wellington and Field Marshal Bluecher.
Wellington would later describe that damp overcast day as "the nearest-run thing you ever saw in your life".
Ten hours of bitter fighting, often hand-to-hand, left more than 10,000 people lying dead on the battlefield of Waterloo and 35,000 wounded, thousands of whom later succumbed to their injuries.
Finally defeated by an alliance of monarchies determined to end years of European war following the 1789 French Revolution, Napoleon was exiled to the island of Saint Helena in the south Atlantic Ocean, where he died in 1821.
After the battle the victors redrew the map of Europe and the continent enjoyed almost a century of relative peace until the carnage of World War I tore it apart again between 1914 and 1918.
France remains ambivalent about Napoleon's memory and the battle has exposed a nerve.
Belgium angered France this month by minting a special 2.5-euro coin to mark the battle after France forced it to scrap a two-euro coin saying it would cause an "unfavourable reaction in France".