Prince William and Catherine, Duchess of Cambridge, have helped launch the Battle of Passchendaele commemorations in Belgium.
The royal couple, both 35, paid tribute to the 54,000 fallen British and Commonwealth soldiers who have no known graves during a visit to the Menin Gate in Ypres, Belgium, on Sunday (30.07.17).
In a touching speech given at the commemorative ceremony, Prince William paid tribute to those who "sacrificed everything for the lives we live today."
He said: "The battlefields of the Salient came to define the war for many British and Commonwealth soldiers.
"The defence of the city at such great cost meant that it became hallowed ground. Winston Churchill said of Ypres, 'A more sacred place for the British race does not exist in all the world.'
"Today the Menin Gate records almost 54,000 names of the men who did not return home. The missing with no known grave. Members of our families, our regiments, our nations, all sacrificed everything for the lives we live today.
"At the memorial's inauguration the British commander Field Marshal Lord Plumer spoke movingly to the assembled families, saying of their lost loved ones: 'He is not missing, he is here.'"
After Prince William's speech, Belgium's King Philippe gave his own moving tribute in which he praised the "struggle" of the battle for allowing people to "enjoy freedom" today.
He said: "Passchendaele was a struggle for freedom, our common freedom, the freedom we enjoy today. At the time it was a fight for land, every possible metre of land. Blood soaked the earth.
"The bodies of the thousands of soldiers who remained here forever became one with the earth. So your graves on our soil have become our graves on your soil. In the same way your Menin Gate has become our gate."
William and Kate continue their Europe tour on Monday (31.07.17) with a visit to a special service at the Commonwealth War Grave's biggest cemetery, Tyne Cot, where they will be joined by UK prime minister Theresa May, and William's father Prince Charles.