After the Soviet armed forces captured eastern Poland from the Germans in 1944 , the Soviets unilaterally declared a new frontier between the Soviet Union and Poland approximately at the Curzon Line , despite the protestations from the Polish government-in-exile in London and the western Allies at the Teheran Conference and the Yalta Conference of February 1945 . After the German surrender on 7 May 1945 , the Allies occupied the remainder of Germany , and the Berlin declaration of 5 June 1945 confirmed the division of Allied-occupied Germany according to the Yalta Conference , which stipulated the continued existence of the German Reich as a whole , which would include its eastern territories as of 31 December 1937 . This did not impact on Poland 's eastern border , and Stalin refused to be removed from these eastern Polish territories
Yalta Conference
Yalta Conference
Refugee