Germany's president paid tribute to Britain for liberating the Nazi concentration camp Bergen-Belsen 70 years ago and restoring "humanity" to the country, at a ceremony Sunday joined by about 70 survivors.
More than 50,000 deportees from across Europe lost their lives at the camp in western Germany between 1941 and 1945, including the young Jewish diarist Anne Frank, in addition to 20,000 prisoners of war.
President Joachim Gauck said British forces who freed the starving camp prisoners led by example during the subsequent Allied occupation.
He quoted Major Ben Barnett, one of the first British officers to reach the camp that spring, remarking on the unspeakable sights he encountered.
"The things I saw completely defy description. There are no words in the English language which can give a true impression of the ghastly horrors of this camp," Barnett said.
Gauck said the Allies were post-war "ambassadors of a democratic culture that did not pursue vengeance against the enemy".
"With their actions and their approach, driven by humanity, a new epoch began. People, the former 'master race', would see that human sympathy can indeed be learned," he said.
"As such, they were the shining counter-example to the advancing Germans who in the years before conquered, subjugated, enslaved and plundered Europe."
The president of the World Jewish Congress, Ronald S. Lauder, noted that the British soldiers gave the world some of the first visual proof of the Holocaust.
"When British troops entered the gates here at Bergen-Belsen - they took pictures, and for the first time, the world finally understood the extent of the Nazi horror," he said.
"We saw the bulldozers pushing naked bodies into open pits. The walking skeletons. The unbelievable sadness and loss."
Lauder urged increased vigilance against a resurgence of anti-Semitic attacks in Europe and far-right parties gaining ground in countries such as Hungary and Greece.
"There is a younger generation of Jews that are committed to making sure that the Jewish people never fall victim to this kind of evil again," he told the assembled survivors.
"We look up to you and we find inspiration."
There is little left of the Nazi camp, torched by British troops shortly after it was liberated on April 15, 1945 to prevent the spread of deadly diseases such as typhus, which killed Anne Frank earlier that year.
Under sprawling green fields where the barracks once stood are several mass graves and a memorial.
Susanna Christiansen, 82, who survived the camp but whose father died three days after the liberation, said it was overwhelming to return.
"I feel emptiness, pain and sadness," she told news agency DPA.
Germany on Sunday also marked the 70th anniversary of liberation by US troops of the Flossenbuerg camp, where some 30,000 prisoners died.
AFP contributed to this report.