At the end of World War II, the Allies formally accepted the unconditional surrender of Nazi Germany. There were extensive changes to the territorial extent of Poland, following the decision taken at the Tehran Conference of 1943 at the insistence of the Soviet Union. The Polish territories east of the Curzon Line (known as the Kresy), which the Soviet Union had occupied in 1939 along with the Bialystok region were permanently annexed, resulting in Poland losing over 20% of its pre-war borders. While a large portion of this area was predominately populated by Ukrainians and Belarusians, most of their Polish inhabitants were expelled. Today these territories are part of Belarus, Ukraine and Lithuania.