A man nicknamed the British Oskar Schindler, who saved hundreds of Jewish children from the Nazis before the second world war and on Monday celebrated his 105th birthday, is to receive the highest honour in the Czech Republic.

Sir Nicholas Winton enabled 669 children – mostly Jewish – to escape from the German-occupied country, then part of Czechoslovakia, and come to Britain over the course of nine months before war broke out in September 1939. Most of the children's families ended up being interned and died in Nazi concentration camps during the war.

The decision to grant Winton the Order of the White Lion was announced by the Czech ambassador, Michael Zantovsky, at an event in London to mark his birthday and the launch of a biography written by his daughter, Barbara Winton.

In a letter to the former stockbroker, the Czech president, Miloš Zeman, said: "You gave these children the greatest possible gift: the chance to live and to be free. But you did not think of yourself as a hero because you were conducted by a desire to help those who could not defend themselves, those who were vulnerable. Your life is an example of humanity, selflessness, personal courage and modesty."

It is estimated that there are around 6,000 people in the world today who owe Winton their lives. It was late in December 1938 when he cancelled a holiday to go to Prague to see what was happening to refugees there. He spent only three weeks in the city – the most leave he could get from his job at home – but it was enough time for him to recognise the impending threat facing the refugees who had arrived following the Nazi invasion of the Czech Sudetenland in October 1938.

He immediately set about organising eight evacuations of the children on the Kindertransport train, a rescue mission organised from Britain. He advertised in newspapers for foster homes, got the necessary permits from the immigration office in the UK, and persuaded the Germans to let the children leave the country. When Winton returned to his job in London on 21 January 1939 he continued the rescue mission, working in the evenings until the last train was cancelled when war broke out in September 1939.

At the reception in the Czech embassy Winton said: "I am always surprised every time I come here to see all kinds of people who have come really very great distances to say hello. As far as I am concerned, it is only anno Domini that I am fighting – I am not ill, I am just old and doddery. And I am more doddery than old."

Ruth Hálová, 88 was one of the children he saved and she had flown over for the party from South Bohemia in the Czech Republic. Others came on Monday from as far as New Zealand and the USA. Hálová was one of the children who came over on one of the Kindertransport journeys and she stayed with a British family throughout the war while her mother was in the concentration camp at Terezín, Czechoslovakia.

"I first met Nicky when he came to visit Yad Vashem in Jerusalem," Hálová said. "I was there just visiting family and they phoned me at 10 o'clock at night and said: 'Nicholas Winton is here!' It was just amazing to meet him and to see him again today. It is never too long or too far to come and see Nicky."

But Hálová would never have met Winton had the story not emerged in 1988 in spectacular fashion on the BBC's That's Life programme, when Winton, sitting in the audience, was astonished to find that most of the rest of the audience were people he had saved.

The programme reunited Winton with one of his party guests, Lord Alfred Dubs, a Labour politician. Dubs's father fled Prague in March 1939 for England and they were reunited when Dubs arrived on the Kindertransport at Liverpool Street station. Dubs has become firm friends with Winton since. He says: "It's not often you can say to somebody: it's thanks to you that I am here at all. I make more speeches because I know Nicky than because of everything else I know."

"Nicky is a national hero in the Czech Republic," says Vera Egermayer, a Holocaust survivor who was interned at Terezín transit camp. "In England, you don't know about him but everywhere else we do. He did a kind act and never told anybody."

Born in 1940 in Czechoslovakia, Egermayer has long known the story of Winton, who was knighted in 2002. Egermayer now lives in New Zealand where she has founded the New Zealand Children's Holocaust Memorial Project.

• This article was amended on 21 May 2014. An earlier version used interred when interned was meant. It was also amended to remove an incorrect reference to a scrapbook telling Nicholas Winton's story being found in a loft.