In July 1945 , at the Potsdam Conference , the Allies placed most former eastern territories of Germany east of the Oder – Neisse line under Polish administration . Article XIII concerning the transfer of Germans was adopted at the Potsdam Conference in July 1945 . It was an emergency measure , drafted and adopted in great haste , a response to the wild expulsions of Germans from Czechoslovakia and Poland , which had created a chaotic situation in the American and British zones of occupation . The Soviet Union transferred territories to the east of the Oder – Neisse line to Poland in July 1945 . Subsequently , most of the remaining Germans were expelled to the territories west of the line
Potsdam Conference
Potsdam Conference
Flight and expulsion of Germans from Poland during and after World War II