Sir Nicholas Winton, the Englishman who organised the rescue of 669 children destined for Nazi concentration camps, has died aged 106.
The British prime minister described him as a "great man" and the chief rabbi praised his "exceptional courage".
He died on the anniversary of the departure of a train in 1939 carrying the largest number of children - 241.
His son-in-law Stephen Watson said he died peacefully in his sleep at Wexham Hospital, Slough near London.
Sir Nicholas brought the children to Britain, battling bureaucracy at both ends, saving them from almost certain death, and then kept quiet about his exploits for a half-century.
He organised a total of eight trains from Prague, with some other forms of transport also set up from Vienna.
The reluctant hero worked to find British families willing to put up £50 to look after the boys and girls in their homes.
Sir Nicholas was knighted by the Queen in March 2003. His work has been likened to that of the "saviour" of Jewish prisoners Oskar Schindler, however it was a comparison he was not particularly fond of.
His son Nick said of his father's legacy: "It is about encouraging people to make a difference and not waiting for something to be done or waiting for someone else to do it.
"It's what he tried to tell people in all his speeches and in the book written by my sister."
Prime Minister David Cameron paid tribute to Sir Nicholas, tweeting: "The world has lost a great man. We must never forget Sir Nicholas Winton's humanity in saving so many children from the Holocaust."
Daniel Taub, Israel's ambassador to the UK, said: "He was a hero of our time, having saved 669 Jewish children from the Nazi regime. His legacy, as a point of light in an era of darkness, will forever be remembered".
Last year, Sir Nicholas was awarded the Order of The White Lion by Czech president Milos Zeman.
Michael Zantovsky, Ambassador of the Czech Republic to the United Kingdom, who was a close friend described him as "a positive man who radiated good".
"It was incredibly moving to be present at some of the gatherings of him with his so-called children and the children of his children. They all owe their existence to him."