A memorial service has been held for Sir Nicholas Winton, who rescued hundreds of children from the Holocaust in the months before World War Two.
Some 28 of those he saved as children were among 400 people who attended the event at London's Guildhall, along with Czech, Slovak and UK government representatives.
Sir Nicholas organised the "Kindertransport" in which 669 mostly Jewish children came to Britain by train from Czechoslovakia in 1939.
He died on 1 July last year, aged 106.
The Kindertransport became public knowledge on BBC TV show That's Life in 1988 when presenter Esther Rantzen reunited some of those saved with the person who helped them escape the Nazis.
Many of the children went on to have their own families and the number currently alive as a result of the Kindertransport is believed to be about 7,000.
Esther Rantzen told the service about the moment two women who were rescued through the Kindertransport met Sir Nicholas on That's Life.
She said: "For the only time in my professional life I had to stop, get off my chair, get to behind the scenery, wipe my eyes, come back again and continue with the programme, because the impact of that moment, when people for the first time had the chance to meet their hero."
Around 130 rescued children and family members travelled from around the world to be at the service.
For part of the service four of them spoke to Esther Rantzen about their experiences of travelling to the UK on the Kindertransport.
One of those was Ruth, who was 13 when she travelled to London.
She said she ended up looking after a baby that travelled with her group and fed the infant with chocolate after its milk bottle smashed.
"My memory of looking out of the window and seeing all of the faces of our relatives, tear-stained and in great worry, will stay with me forever," she said.
Ruth said she had regarded Sir Nicholas as a father, adding: "He was the most human exemplar of humanity we shall ever find."
Another of those rescued, Hugo, praised the parents who sent their children on the Kindertransport as well as Sir Nicholas.
He added that Sir Nicholas had "inspired" parents with his confidence, after which support for the Kindertransport had "spread like fire".
At the scene
by Mario Cacciottolo, BBC News
The grand surroundings of the Guildhall buzzed with the warm rumblings of friends, dignitaries and families as people gathered to celebrate the life of the man they knew as "Nicky".
While a pianist stroked the keys of a black grand piano, some of those who were on the Kindertransport filed in beneath the hall's grand arches, bringing their sons and daughters with them.
All of these people form part of what is known as Sir Nicholas Winton's extended family.
When the event began, Sir Nicholas's daughter, Barbara, paid tribute to her father, saying they were all gathered to "squeeze into an hour his long life", which she also said had been one of "love, laughter, passion and commitment".
Eva Paddock, 80, who now lives in Cambridge, Massachusetts in the US, took that life-saving journey with her sister when she was three.
"I have my family with me and for us it's a rite of passage. Nicky was an exemplar of a person who acted when something needed to be done.
"It's very emotional and very moving to be here. It feels very important to be here with my extended family."
One of the Kindertransport children, Hana Isaac-Kleiner, now 88, told the BBC that Nicholas Winton saved their lives.
She said: "He was one of the few on the team in Prague who were well-enough informed about what was happening in Germany and Austria to realise that the danger to Jewish people was imminent."
Another, Kurt Taussig, 92, from Stanmore, Harrow, said he usually did not come to Kindertransport events but would have "swum an ocean to be here".
"What that man did has never been done before or again. He was completely unique in achieving a miracle."
Mr Taussig spent seven years in the RAF after coming over on the Kindertransport.
The Briton who saved children from the Holocaust
- Sir Nicholas was born Nicholas Wertheimer in 1909 to Jewish parents
- By 1938 he was a young stockbroker in London
- He dropped everything to go to Prague to help Jewish refugees fleeing Nazi occupation
- Sir Nicholas organised foster families for Jewish children in Britain, placing adverts in newspapers
- The 669 children travelled on eight trains across four countries
- Sir Nicholas's team persuaded British custom officials to allow all the children in despite incomplete documentation
Others present at the service included Lord Alfred Dubs, Lady Milena Grenfell-Baines and the Rev John Fieldsend, who were all part of the Kindertransport, as well as representatives from the German and Swedish embassies.
The service also had contributions from Lord Dubs and former Czech ambassador Michael Zantovsky.
Asked what message people should take from Sir Nicholas's life, Lord Dubs said: "I think what they should see is the story the triumph of the human spirit where one individual said he is going to do something and save lives from the Holocaust and he did it."
Sir Nicholas continued community work in later life in Maidenhead, Berkshire.
His surviving children Nick and Barbara Winton speak at events around the world about how one person can change lives.
Barbara Winton wrote his biography If It's Not Impossible, the title of which is taken from his motto: "If something is not impossible there must be a way of doing it."
A separate memorial concert is to take place on Friday at St John's Smith Square in central London, including readings by actors Jason Isaacs and Rupert Graves and music from cellist Alexander Baillie, raising funds for current child refugees.