His wife found a list of 669 names in the attic

On 14 March 1939 the first of eight trains chartered by Nicholas Winton left Prague. He was a twenty-nine-year-old London stockbroker who had swapped his skiing holiday for a trip to Prague. By August he had got 669 children out, almost all of them Jewish, and handed them over at Liverpool Street to British foster families.

Each child needed a foster family and a fifty-pound guarantee lodged with the Home Office. Winton found them through newspaper adverts, put up guarantees out of his own pocket and forged entry permits because the legal ones took weeks.

The ninth train, with 250 children on its lists, was due to leave on 1 September 1939. That day Germany invaded Poland, the borders closed and the convoy never left the platform. Of those 250, almost nothing was ever heard again.

Winton went back to his office and said nothing for fifty years. In 1988 his wife, Grete, went up to the attic of the house in Maidenhead and opened a leather briefcase: inside were the typed lists, the passport photographs of all 669 and the letters from the parents who had said goodbye to them.

The scrapbook reached the BBC. On "That's Life!" they sat Winton in the front row without telling him why; Esther Rantzen asked whether anyone in the studio owed him their life, and the entire row behind him stood up. He died on 1 July 2015, aged 106: around six thousand people alive today are descended from those 669 children.