Soon after the formation of the Soviet Union, emigration restrictions were put in place to keep citizens from leaving the various republics of the USSR,[1] though some defections still occurred.
During and after World War II, similar restrictions were put in place in non-Soviet countries of the Eastern Bloc,[2] which consisted of the communist states of Central and Eastern Europe (except for non-aligned Yugoslavia).
[3][4] Until 1952, however, the Inner German border between East and West Germany could be easily crossed in most places.
[8] Although international movement was, for the most part, strictly controlled, there was a steady loss through escapees who were able to use ingenious methods to evade frontier security.
[10] The following list of Eastern Bloc defectors contains notable defectors from East Germany, the Soviet Union, Poland, Bulgaria, Romania, Czechoslovakia, Hungary, and Albania before those countries' conversions from communist states in the late 1980s and early 1990s.