In the effect of the Nazi-Soviet Alliance and the Polish Defensive War of 1939, the area was captured by the Soviet Union, which transferred parts of present "Vilnius County" and Utena County to Lithuania, only to annex it the following year. In 1941, it was conquered by the Nazi Germany. During World War II, the area saw formation of many resistance units, most notably the Polish Home Army and, after 1943, the Soviet partisans. After the war, Vilniaus Apskritis existed as a relic of the pre-war independent state in Lithuanian SSR between 1944 and 1950. In this period, significant part of its population moved to Poland during so-called repatriation.