In 1939, at the age of 15, Emil Lowenstein, of Kingsley Way, Hampstead Garden Suburb, boarded a train in Berlin destined for Britain, not knowing if he would ever see his parents again.

The 89-year-old was one of 10,000 children who fled to Britain before the start of the war to escape the Nazis, as part of a rescue mission known as the Kindertransport. He is now a great-grandfather of 20.

“Of the 10,000 children transferred via Kindertransport, I would think 90 per cent didn’t see their parents again because they were in concentration camps,” said Mr Lowenstein.

“Lots of my friends had their parents killed during the war. I lost lots of uncles and aunts.

“We had a very big burden on our shoulders. We all understood much more than children today – we knew the danger and we knew our life was on a knife’s edge. Children have a very different mindset today.

“I’m very pleased about it because I wouldn’t want any children to be in the position we were in.

“If the world forgets what happened in Germany, then the world is not a world worth living in. The Holocaust was unbelievable. It is vitally important that the world knows about it.”

Child psychologist Dr Ben Levy, 32, of Finchley Road, Temple Fortune, is one of Mr Lowenstein’s eight grandchildren. He believes Holocaust Memorial Day should not solely commemorate atrocities committed by the Nazis.

“There have been many atrocities since the Holocaust – there have been mad cap regimes all over the world that have taken over countries and oppressed minorities,” he said.

“My view is that these other atrocities have been equally horrific so I think it’s important to have a day to remember people who have been affected by any ideological attempt at mass annihilation.

“It’s to affirm the idea that someone has an identity that is valuable, at the very least we should tolerate that.

“We should never wish to erase a community or mindset which is different from our own, which is what the Holocaust was all about.”