But when Winton died at the age of 106, Britain's prime minister said that his actions were something the world should always remember.
"The world has lost a great man," Prime Minister David Cameron tweeted Wednesday. "We must never forget Sir Nicholas Winton's humanity in saving so many children from the Holocaust."
In the late 1930s, Adolf Hitler's stormtroopers marched into Czechoslovakia and the Jewish population found itself on the Nazi hit-list.
Moved by what he'd seen on a trip to Prague, Winton -- then a young stockbroker -- returned to London and began organizing evacuations of children in 1939. He marshaled a team of volunteers to outwit immigration restrictions, and arranged for British families to open their homes when other countries shut their doors.
"By day, Winton worked at his regular job on the Stock Exchange, and then devoted late afternoons and evenings to his rescue efforts," a profile on the United States Holocaust Memorial Museum's website says
. "He made a great effort to raise money and find foster homes to bring as many children as possible to safety."
It wasn't an easy task; he had to arrange train rides out of Prague, find foster families who'd take in the children and even forge immigration documents.
For nearly 50 years, Winton's efforts -- which saved 669 children, most of them Jewish, from certain death -- were virtually unknown.
But after his wife, Grete, found an old scrapbook that included pictures of the children and detailed the evacuations, she persuaded her husband to tell his story
. It was featured on a BBC TV program in 1988 and later became the focus of a documentary film, "Nicholas J. Winton -- The Power of Good
Over the years, Winton reunited with some of the people he saved on the eight transports he arranged out of Prague. Some still call themselves "Winton's children" in his honor.
A ninth transport with 250 children aboard was scheduled to leave the city on September 1, 1939. But Germany invaded Poland that day, putting an end to Winton's rescue efforts as the borders controlled by Germany were closed, according to an account on the website for "The Power of Good."
In the film, Winton said the image of those children he couldn't save still haunted him.
"If the train had been a day earlier, it would have come through," he said. "Not a single one of those children was heard of again, which is an awful feeling."
'Hero of the Holocaust'
His son, Nick Winton, confirmed his death to CNN. His daughter and two grandchildren were with him when he died, according to the Rotary Club of Maidenhead, of which Winton was a member.
Winton was sometimes called Britain's Oskar Schindler, after the German businessman who was credited with saving the lives of 1,200 Jews during the Holocaust -- in which 6 million people were killed.
It was a well-deserved comparison, the president of the European Jewish Congress said in a statement.
"I want to pay tribute to a hero of the Holocaust who more than earned his title of the 'British Schindler,'" Viatcheslav Moshe Kantor said in a statement. "At a time of increasing uncertainty and insecurity for European Jewry, Sir Nicholas' legacy reminds all of us that courage in the face of adversity does make a difference, and only with perseverance can we achieve change."
Knighted for valiant service
Winton was knighted by Queen Elizabeth II in 2003 for services to humanity.
Last year, the Czech Republic honored him with the Order of the White Lion, its highest honor.
On a website maintained by his family, photos show Winton meeting with dignitaries, celebrating a recent birthday with people he helped save and presenting a human rights award to Malala Yousafzai.
In 2007, Winton returned to Prague to give a speech at a forum organized by former Czech President Vaclav Havel.
"One can only hope somehow or other, goodness, kindness, truth, honor will prevail," Winton told the crowd
, "and people will realize it's not good enough just to say, 'Today I have done no harm. I've been a good person,' but should have been able to say, 'I was given the opportunity today and I did do some good.'"