Through another socialist friend, Martin Blake, Winton became part of a left-wing circle opposed to appeasement and concerned about the dangers posed by the Nazis. At school, he had become an outstanding fencer and was selected for the British team in 1938. He had hoped to compete in the following Olympics, but the games were cancelled because of the war. Shortly before Christmas 1938, Winton was planning to travel to Switzerland for a skiing holiday. He decided instead to visit Prague and help Martin Blake, who was in Prague as an associate of the British Committee for Refugees from Czechoslovakia, then in the process of being occupied by Germany, and had called Winton to ask him to assist in Jewish welfare work. Winton established an organisation to aid children from Jewish families at risk from the Nazis. He set up his office at a dining room table in his hotel in Wenceslas Square. In November 1938, following "Kristallnacht" in Nazi-ruled Germany, the House of Commons approved a measure to allow the entry into Britain of refugees younger than 17, provided they had a place to stay and a warranty of £50 was deposited for their eventual return to their own country. An important obstacle was getting official permission to cross into the Netherlands, as the children were to embark on the ferry at Hook of Holland. After "Kristallnacht" in November 1938, the Dutch government officially closed its borders to any Jewish refugees. The Dutch police, the "marechaussee", searched for them and returned any found to Germany, despite the horrors of "Kristallnacht" being well known. Winton succeeded, thanks to the guarantees he had obtained from Britain. After the first train, the process of crossing the Netherlands went smoothly. Winton ultimately found homes in Britain for 669 children, many of whose parents would perish in the Auschwitz concentration camp. His mother worked with him to place the children in homes and later hostels. Throughout the summer of 1939, he placed photographs of the children in "Picture Post" seeking families to accept them. By coincidence, the names of the London and North Eastern Railway steamers which operated the Harwich to Hook of Holland route included the "Prague" and the "Vienna"; the former can be seen in a 1938 Pathé newsreel. He also wrote to US politicians such as President Franklin D. Roosevelt, asking them to take more children. He said that two thousand more might have been saved if they had helped, but only Sweden took any besides those sent to Britain.