 The millions of Germans still remaining in these areas under the Potsdam Agreement were over a period of several years expelled and replaced by Polish settlers (see Expulsion of Germans after World War II), while millions of ethnic Germans from other Eastern European countries poured into Allied-occupied Germany.This migration was to such an extent that by the time the German Democratic Republic was founded, between a third and a quarter of the population of East Germany was "Heimatvertriebene", i.e.ethnic German migrants who fled or were expelled as part of a wider trend of population transfer among the countries and regions of Eastern Europe following World War II.