After the fall of tsarist Russia, fighting broke out for control over the city and surrounding region. During the Soviet occupation (Polish–Soviet War), the unsuccessful Nieśwież uprising by Polish residents took place during March 14–19, 1919. However, Nieśwież was recaptured by Poles on April 19, 1919 and re-integrated with the reestablished Polish state. It was became a powiat in the Nowogródek Voivodeship until the Soviet invasion of Poland in September 1939. During World War II, from 1939 to 1941 it was under Soviet occupation, from 1941 to 1944 under German occupation, and from 1944 to 1945 under Soviet occupation again, before it was once more taken from the territory of Poland and annexed by the Soviet Union, in accordance with the Potsdam Agreement.