region, roughly corresponding to the territory of the earlier Belostok Oblast. At the end of World War I the city became part of the newly independent Second Polish Republic, as the capital of the Białystok Voivodeship (1919–1939). During the 1919–1920 Polish–Soviet War, possession of the city by the Red Army and the Provisional Polish Revolutionary Committee occurred during the lead up to the Battle of Warsaw. During the resultant counteroffensive, the city returned to Polish control after the Battle of Białystok. After the wars and the reestablishment of independent Poland, Polish education in Białystok was restored and the textile industry was revived. A municipal public library was established, sports clubs were founded, including Jagiellonia Białystok, and in the 1930s a drama theater was built. With the beginning of World War II, Poland was invaded by Nazi Germany and the Soviet Union. Initially Białystok was briefly occupied by Germany, and the German Einsatzgruppe IV entered the city on September 20–21, 1939 to commit crimes against the population. Afterwards, the Germans handed the city over to the Soviet Union, as a result of the Molotov–Ribbentrop Pact. Under Soviet occupation, it was incorporated into the Byelorussian SSR from 1939 to 1941 as the capital of Belastok Region. Polish people were subject to deportations deep into the USSR (Siberia, Kazakhstan, Far North). Pre-war mayor Seweryn Nowakowski was arrested by the NKVD in October 1939 and probably also deported to the USSR, however his fate remains unknown. The NKVD took over the local prison. The Polish resistance movement was active in the city, which was the seat of one of the six main commands of the Union of Armed Struggle in occupied Poland (alongside Warsaw, Kraków, Poznań, Toruń and Lwów). Białystok native and future President of Poland in exile Ryszard Kaczorowski was a member of the local Polish resistance and was arrested in the city by the NKVD in 1940. Initially the Soviets sentenced him to death, but eventually he was sentenced to 10 years in forced labor camps and deported to Kolyma, from where he was released in 1942, when he joined the Anders' Army. In the course of the German invasion of the Soviet Union in 1941, Białystok was occupied by the German Army on 27 June 1941, during the Battle of Białystok–Minsk, and the city became the capital of Bezirk Białystok, a separate region in German occupied Poland, until 1944. The Great