In 1945 , Silesia was captured by the Soviet Red Army . By then a large portion of the German population had fled or were evacuated from Silesia fearing the Soviets . Under the terms of the agreements at the Yalta Conference and the Potsdam Agreement , both in 1945 , German Silesia east of the rivers Oder and Lusatian Neisse was transferred to Poland ( see Oder-Neisse line )
Yalta Conference
Yalta Conference
History of Silesia