The Duke and Duchess of Cambridge have described their visit to a Nazi concentration camp as "shattering", saying the site is a "terrible reminder of the cost of war".
William and Kate heard first hand about the horrors of Stutthof camp, now run as a museum, from survivors and also made a private tour of the site's crematorium, where the bodies of thousands of prisoners were burned.
The couple saw other evidence of the Nazi's attempts to exterminate the Jews, from a display of hundreds of pairs of shoes from Holocaust victims to the tiny wooden huts where prisoners slept three to a bunk.
William and Kate appeared in sombre and reflective mood as they toured the site, but the Duchess was not moved to tears.
The couple left a message in the visitors' book which they both signed: "We were intensely moved by our visit to Stutthof, which has been the scene of so much terrible pain, suffering and death.
"This shattering visit has reminded us of the horrendous murder of six million Jews, drawn from across the whole of Europe, who died in the abominable Holocaust.
"It is, too, a terrible reminder of the cost of war. And the fact that Poland alone lost millions of its people, who were the victims of a most brutal occupation.
"All of us have an overwhelming responsibility to make sure that we learn the lessons and that the horror of what happened is never forgotten and never repeated."
Later the couple visited the Polish port city of Gdansk, where large crowds turned out to see them.
British survivors of the concentration camp, Manfred Goldberg and Zigi Shipper, both 87, from London, made a special trip to the Stutthof camp - the first time they had returned to the site - to meet William and Kate and recount their experiences.
Mr Goldberg, who spent two phases of the war at the camp, said: "When I was here they found that the gas chamber was too small for their purposes - they couldn't gas people fast enough. They brought in two goods wagons on a railway line running at the back of the camp.
"They got engineers to make them air-tight and they used those as auxiliary gas chambers so they could kill people faster. Then they had the second problem because the crematorium couldn't burn the bodies fast enough, so periodically bodies were being piled up.
"A row of bodies, a row of timber, a row of bodies, a row of timber, until it was a sizeable pile and they would set fire to it and try to dispose of the bodies, in addition to the crematorium working 24 hours a day - those are some of memories from here."
He added: "I was feeling extremely nervous, I agonised before I agreed to come here, because I felt I'd put it all behind me. Nervous at facing the trials and tribulations.
"In 1946 when I was a youngster I was admitted to England, I didn't dream I would ever have the privilege of shaking the hand of a future King of this country."