British humanitarian Sir Nicholas Winton, who is best known for saving hundreds of Jewish children in Czechoslovakia before the outbreak of World War II, died of respiratory failure in England on Wednesday. He was 106 years old.

According to a Naomi Koppel of the Independent, Winton earned the label of "Britain's Schindler" after he helped save 669 Jewish children from the Holocaust. While he was born to parents of German-Jewish descent, he and his family converted to Christianity.

"The world has lost a great man," British Prime Minister David Cameron wrote on Twitter Wednesday. "We must never forget Sir Nicholas Winton's humanity in saving so many children from the Holocaust."

According to the Independent, Winton worked as a clerk at the London Stock Exchange back in 1938. During that time, a friend urged him to travel to Czechoslovakia and cancel their skiing holiday.

"Alarmed by the influx of refugees from the Sudetenland, which had recently annexed by Germany, Winton and his friend feared, correctly, that Czechoslovakia would soon be invaded by the Nazis and that Jewish residents from there would be sent to concentration camps," Koppel wrote.

According to Catherine E. Shoichet and Don Melvin of CNN, Winton went back to London and started organizing evacuations of children in 1939. He arranged the logistics of the operation by gathering volunteers to outsmart immigration restrictions and convince British families to open their homes to the affected children.

"It wasn't an easy task," Shoichet and Melvin wrote. "He had to arrange train rides out of Prague, find foster families who'd take in the children and even forge immigration documents."

CNN reported that Winton was able to get eight transports full of Jewish children out of reach from Adolf Hitler and the Nazis. However, a ninth transport with 250 children failed to depart on Sept. 1, 1939, the day World War II officially began.

"If the train had been a day earlier, it would have come through," Winton said. "Not a single one of those children was heard of again, which is an awful feeling."

The Independent reported that while many more Jewish children were saved from Berlin and Vienna, Winton's operation stood out because he largely conducted them on his own.

"Maybe a lot more could have been done. But much more time would have been needed, much more help would have been needed from other countries, much more money would have been needed, much more organization," Winton said.

Winton acknowledged that there were some problems with how the children were treated by some foster parents. Some of them even worked as cheap servants.

"I wouldn't claim that it was 100 percent successful," Winton said. "But I would claim that everybody who came over was alive at the end of the war."

CNN reported that Winton's efforts to save children from the Holocaust were virtually unknown for nearly 50 years. It only came to light after his wife, Grete, found an old scrapbook that had pictures of the children and details of the evacuations.

"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,'" Shoichet and Melvin wrote.

According to CNN, Queen Elizabeth II knighted Winston in 2003 for services to humanity. The Czech Republic awarded him last year its highest honor, the Order of the White Lion.

"One can only hope somehow or other, goodness, kindness, truth, honor will prevail," Winston said in a 2007 speech in Prague. "People will realize [that] 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.'"

The Independent reported that Winston never described himself as a hero, always staying modest about his achievements.

"Everybody said, 'Isn't it wonderful what you've done for the Jews? You saved all these Jewish people,'" Winton said. "When it was first said to me, it came almost as a revelation because I didn't do it particularly for that reason. I was there to save children."

According to CNN, Winton is survived by his son, Nick, his daughter, and two grandchildren.