The children on the #Kindertransport came from Germany, Austria, Czechoslovakia, Poland, and the Free City of Danzig. Most, but not all, were Jewish. Often they were the only members of their families who survived the Holocaust.
Starting with the #Kindertransport, which brought 10,000 unaccompanied children to England during the nine months prior to the outbreak of the Second World War. You can view a 1938 newsreel on the British Pathé website: https://www.britishpathe.com/video/jewish-child-refugees