Between 27 January and 13 February 1939, half a million people crossed the border, making their way into France. The French authorities set up improvised refugee camps in Roussillon. Most of those who fled into exile remained in France, while others set off to America, the USSR and or Czechoslovakia. Great Britain accepted the skilled and educated, welcoming intellectuals, doctors and experts in civil defence. The Catalans exiled in France experienced the Nazi occupation. Thousands of them were killed in extermination camps; others fought with the Resistance or in the allied armies.