The Queen has paid tribute to thousands of Canadian troops who lost their lives in World War I as she unveiled a restored monument in France.
The Queen said the Canadians showed "conspicuous bravery"
The memorial remembers the bitter Battle of Vimy Ridge in which more than 3,500 Canadian soldiers died.
She was joined at the memorial, near Lille, by Canadian Prime Minister Stephen Harper and his French counterpart, Dominique de Villepin.
The ceremony featured prayers, the Last Post and a minute's silence.
The Queen said it was at the Battle of Vimy Ridge, which took place on Easter Monday 90 years ago, that Canadian troops scored a major victory that inspired Allied forces.
"No fewer than four Canadians were awarded the Victoria Cross for conspicuous bravery in the battle, though it could easily be said that every solider in the field demonstrated conspicuous bravery, such was the verve of the Canadian attack," she said.
"It was a stunning victory. More(over), in capturing this formidable objective, the Canadian corps transformed Vimy Ridge from a symbol of despair into a source of inspiration."
Designed by sculptor and architect Walter Seymour Allward, the monument was first unveiled by the Queen's uncle, King Edward VIII, in 1936.
It features 27-metre high pylons, 20 sculpted figures and inscriptions of the names of 11,285 Canadian soldiers listed as "missing, presumed dead" during World War I.
It has undergone a major two-year restoration programme.
The Queen, accompanied by the Duke of Edinburgh, was also joined by Canadian war veterans, serving Canadian military personnel and Royal Canadian Mounted Police.
The Queen and the Duke also laid a wreath before holding a brief walkabout among the audience and chatted to war veterans and Canadian young people.