the defeat of Imperial Germany in World War I, a plebiscite was held on 20 March 1921 in Oppeln to determine if the city would be in the Weimar Republic or become part of the Second Polish Republic, which just regained independence. 20,816 (94.7%) votes were cast for Germany, 1,098 (5.0%) for Poland, and 70 (0.3%) votes were declared invalid. Voter participation was 95.9%. Results of the plebiscite in the Oppeln-Land county were different, with 30% of the population voting for Poland. Oppeln was the administrative seat of the Province of Upper Silesia from 1919–1939. In the years 1928–1931, by the decision of the German regional administration, the Piast Castle was demolished. Thanks to the strong opposition of the local Polish community and protests of the Union of Poles in Germany, the castle tower was saved from demolition. Nowadays called the Piast Tower it is one of the city's landmarks. In 1929, a Polish theatre from Katowice came to Opole to perform the opera Halka by Stanisław Moniuszko. After the performance, the actors were brutally beaten by a German militia with the silent consent of the German police. Local Polish activists were intensively persecuted from 1937 onwards. The local Gestapo terrorized and spied on Polish activities in the German-held part of Upper Silesia, participated in espionage and sabotage in the Polish part of Silesia and prepared border provocations against Poland. There was strong anti-Polish propaganda in the city and region. The local Polish newspaper Nowiny Codzienne was frequently confiscated from 1937 and its editors were harassed, its work obstructed, its distributors persecuted, and its readers threatened. In 1938–1939, the local Gestapo carried out expulsions of Polish activists from the region, which the local Polish press could still report. On July 2, 1939, a Nazi militia attacked and severely beat Poles going to a Polish service in the Saint Sebastian Church. World War II On August 31, the day before the German invasion of Poland that began World War II, the Germans began mass arrests of prominent Poles in the city, which were continued in September. Among the arrested Poles were activists, entrepreneurs, journalists, editors, scout leaders, the director of the local Polish bank and the director of the local Polish library. The Nowiny Codzienne newspaper was closed down on September 1, and its editorial team, including editor-in-chief Jan Łangowski, was deported to concentration camps. In September 1939, local Polish organizations