As the invasion of Poland progressed throughout September 1939, the Polish government evacuated into Romania and from there to France. Based at first in Paris, it moved to Angers until June 1940, when France capitulated to the Germans. With the Fall of France, the Polish Government-in-Exile relocated to London, along with a first wave of at least 20,000 soldiers and airmen in 1940. It was recognized by all the Allied governments. Politically, it was a coalition of the Polish Peasant Party, the Polish Socialist Party, the Labour Party, and the National Party. Although these parties maintained only a vestigial existence in the circumstances of the war, the tasks of the Government-in-Exile were immense, requiring open lines of communication with, and control of, the Polish Underground State "in situ" and the Polish Underground Army in occupied Poland, and the maintenance of international diplomatic relations for the organization of regular Polish military forces in Allied states.