Rehabilitation of Volksdeutsche
During the war the population of the annexed areas of Poland was classified by the Nazis in different categories according to their "Germanness" in the Deutsche Volksliste. While most of the Volksdeutsche population of pre-war Poland fled or was expelled, some were rehabilitated and offered their pre-war Polish citizenship back. While those who had signed Volksliste category "I" were expelled, rehabilitation was offered to people who had been subject to forced labour before, spoke Polish and were rated as not constituting a threat. Once granted Polish citizenship, they were encouraged to Polonize their names, or to restore their original Polish names them if they had been Germanized during the war. Numbers of how many were offered to stay in Poland as Poles and eventually did are not available, but it is assumed that the vast majority had rather opted and left for Germany by 1960. Those of mixed descent from within or without the borders of pre-war Poland were also allowed to stay on the premise of Polonization, yet likewise no comprehensive data exists.
Read more about this topic: Flight And Expulsion Of Germans From Poland During And After World War II