Under the terms demanded by the Soviet Union in the Potsdam Agreement , the region was put under Polish administration after the Potsdam Conference and eventually became part of Poland . Germans remaining in the region were expelled , and were replaced with Poles , some of whom were from Central Poland , and some of whom had themselves been expelled from the Polish areas annexed by the Soviet Union . A small part of the German population , mostly technicians for the water supply companies , were retained and used for compulsory labour ; they were allowed to emigrate to Germany in the 1950s . Older estimates indicated that of the pre-war population of 645,000 , only 5,000 of the inhabitants from 1939 remained in the province in 1950
Potsdam Conference
Potsdam Conference
Neumark