The Queen honoured soldiers from Canada and other Commonwealth countries in Belgium on Thursday, laying wreaths at the vast gravesite in Passchendaele, where some 500,000 soldiers never returned home or were wounded in one of the bloodiest battles during the First World War.

The Queen, centre, and Belgium's Queen Paola, right, walk away from Tyne Cot Cemetery after a ceremony in Passchendaele, Belgium, on Thursday .
(Francois Lenoir/Associated Press)

Canada was represented at the 90th anniversary of the battle by Veterans Affairs Minister Greg Thompson and Indian Affairs Minister Jim Prentice, who joined Belgian royals and other dignitaries from Australia, New Zealand and Britain. About 4,000 locals also looked on in windy and wet conditions while mournful bagpipes played.

The wreaths were put at the foot of a large white cross cenotaph that dominates the gravesite. A vintage biplane flew overhead and spread red poppy petals over Tyne Cot in tribute to the dead.

The cemetery at Tyne Cot is the largest Commonwealth military burial site in the world, located just a few kilometres from the tiny village of Passchendaele, which gave its name to one of the last battles of attrition of the war.

The Queen, dressed in a purple overcoat and matching coloured hat, also opened a new visitors' centre at the cemetery, originally a fortification used by the Germans against advancing British-led forces in 1917.

Many among the crowd at the cemetery had family links to the battle.

"My father told me about the mud, the rain and the men dying in shell holes full of water, drowning," said Joe Hubble, 75, a retired member of the Blackwatch Regiment, from Kent in southeast England. He visits Flanders Fields every year.

Symbol of brutal trench warfare

Also attending the anniversary was the Australia's governor general, Maj.-Gen. Michael Jeffery, and New Zealand's Gov. Gen. Anand Satyanand.

There are 12,000 graves and 35,000 names of missing persons engraved on memorial walls at Tyne Cot, situated on a ridge captured by Australian forces during the battle in 1917. It overlooks the nearby city of Ieper that was better known to the soldiers of 1914-18 by its French name, Ypres.

The battle became a symbol of utter destruction and senseless killing in brutal trench warfare carried out in days of endless rain, back-and-forth volleys of millions of shells creating a cratered landscape littered with dead bodies and flattened villages.

It also saw the first use of mustard gas. Even now, the remains of soldiers, bombs and gas canisters are still dug up every year by farmers plowing the region's fields.

"Passchendaele is the lowest of the low; it's the place in popular memory where the general sends the soldier off to die, in fruitless battles where soldiers are slaughtered in the mud, held up by wire and more troops are behind them," said Tim Cook, a Canadian war historian.

The battle was called to a halt after Canadian reinforcements replaced devastated British, Australian and New Zealand units near Passchendaele and captured the ruined village on Nov. 10, 1917.