After the war , according to the preliminary agreements of the conferences of Yalta and Potsdam , the German territories east of the Oder-Neisse line — most of Pomerania , Silesia and East Prussia — were transferred to Poland and from the middle of 1945 through to 1946 the surviving Germans were expelled . The city was settled by Poles , most of whom were expelled from the former Polish eastern territories annexed by the Soviet Union ( around 80 % at the end of 1945 ) and the rest were mainly repatriates from the Soviet Union and Poles returning from Germany . Also Ukrainians and Lemkos settled into the town during Operation Vistula
Yalta
Yalta Conference
Słupsk