Standing in the ruins of Bergen Belsen just two years after it was liberated, chatting to children who had lost their entire families to the Nazis and survived unthinkable horrors, Greville Janner could hardly have predicted just how much the experience would shape his future.
"It changed my life," he says. "I saw what had happened to the Jewish people. Those children in the Kinderheim at Bergen Belsen changed my whole vision of life."
A former Labour MP, Lord Janner set up the Holocaust Educational Trust (HET) with party colleague Lord Merlyn Rees in 1988. This week he will be awarded the title of Founding Patron at the Trust's annual dinner.
Lord Janner was still a teenager when he first went to Germany as the youngest war crimes investigator in the British army, and vowed then to fight to prevent such an atrocity happening "not just to Jews but to anyone, ever again".
In the 65 years since, he has done more than almost anyone else to strengthen awareness of the Holocaust and bring its lessons into the public consciousness. For two decades it has been largely a given that the history of the Holocaust is taught in schools; it is easy to forget that until 1991, it did not feature on the national curriculum, and that the change was due in no small part to the efforts of HET.
Before that, says Lord Janner, there was "a gap in teaching children. It was different in different schools, and with different teachers - some did it, and some didn't. But there was no absolute overall requirement that they should."
Nowadays, the 84-year-old says he is delighted by the bipartisan support for Holocaust education programmes, in particular the trust's Lessons from Auschwitz scheme, which takes British sixth-form students to Poland to educate them first-hand about the horrors of the Nazi era.
But landmark achievements, such as pushing the War Crimes Act through Parliament in 1991 or winning approval to hold the Nazi looted gold conference in London in 1997, were not always easily come by. In his early political career - in 1970, he won the Leicester North-West seat vacated by his father, serving as a Labour MP until 1997 - he recalls endlessly urging his colleagues and government departments to support him, and being profoundly shocked when people were reluctant to do so.
"We've had to work on it all the time, with everybody," he says. "It was a lot of very hard work."
He always felt that the war crimes investigations in the immediate aftermath of the Holocaust did not go far enough. "There was nobody who pushed it, there were other things to do," he says. But he says that just because it did not happen then, is no reason war criminals should not be hunted down today.
When Sobibor guard John Demjanjuk was found guilty of war crimes at the age of 91, Lord Janner expressed the view that "no concessions to age or the time that has passed can be made when it comes to justice for crimes of this magnitude".
In July, Ladislaus Csizsik-Csatáry was charged in Hungary over alleged involvement in the deportation of 15,700 Jews to Auschwitz. He is 97.
"I don't care what bloody age they are," says Lord Janner. "These criminals should have been dealt with years ago."
But as he acknowledges, it is becoming more and more unlikely that the perpetrators of the Holocaust will be caught and tried. And, sadly, HET is facing up to educating youngsters about what the Nazis did without first-person testimony.
"In the past we have had a large number of survivors who have gone round schools and spoken about their experiences, the murders they saw," he says. "When survivors aren't alive anymore, we won't be able to do it the same way."
Instead, HET is shifting the focus to the children of survivors, who can speak with authority about their parents' experiences. It is continuing creating student ambassadors who have seen Auschwitz and other camps for themselves and can share the experience with their peers. The trust is launching a Greville Janner scholarship fund to enable committed students to take part in specialised educational activities.
"We've got to keep the vision alive," stresses Lord Janner. "While the memory of the Holocaust is vivid in the public mind, it will not recur, but when it has disappeared, it can. And I think the situation today is more dangerous than it has been because antisemitism is growing."
He is particularly worried about the rise of far-right groups in Europe, and the threats to religious traditions, including circumcision, against a backdrop of economic uncertainty. "The questioning of kosher slaughter is increasing in different parts of Europe in a way not seen since the war," he says. "I think we have to worry. When people are suffering they've got to blame somebody for the way things are going. Now they don't just blame the Jews today, they blame other minorities. The Jewish community must work with other minority groups in Britain and in Europe to fight this."
But the former president of the Board of Deputies thinks the community is unified enough to take on its enemies. He cites the rise in places at Jewish schools and says that overall, the Jewish community is strong and getting stronger.
He also says that in Britain Jews are better off than Jews elsewhere in Europe, scoffing at suggestions that, after selecting Ken Livingstone as its mayoral candidate, Labour can no longer represent the interests of the community.
"Right across this country we're very lucky that we've got people who are against antisemitism irrespective of what party they are. The level of antisemitism is much lower in this country than other European countries and I think we are very lucky."
He does worry that the language of the Holocaust is being misused, or trivialised, describing comparisons between Israel and Nazi Germany as "monstrously ridiculous". He warns that the Holocaust must always be seen as unique, but adds that "Jews have to fight not just for the Jews, but for others who are attacked because of their race, religion or colour".