of Poland as a state in 1918, when many moved to Poland. Antisemitic riots occurred in 1923. The city boundaries were expanded between 1925 and 1930 to include an area of with a population of 600,000. In 1929, the Werkbund opened WuWa () in Breslau-Scheitnig, an international showcase of modern architecture by architects of the Silesian branch of the Werkbund. In June 1930, Breslau hosted the Deutsche Kampfspiele, a sporting event for German athletes after Germany was excluded from the Olympic Games after World War I. The number of Jews remaining in Breslau fell from 23,240 in 1925 to 10,659 in 1933. Up to the beginning of World War II, Breslau was the largest city in Germany east of Berlin. Known as a stronghold of left wing liberalism during the German Empire, Breslau eventually became one of the strongest support bases of the Nazi Party, which in the 1932 elections received 44% of the city's vote, their third-highest total in all Germany. KZ Dürrgoy, one of the first concentration camps in Nazi Germany, was set up in the city in 1933. After Hitler's appointment as German Chancellor in 1933, political enemies of the Nazis were persecuted, and their institutions closed or destroyed. The Gestapo began actions against Polish and Jewish students (see: Jewish Theological Seminary of Breslau), Communists, Social Democrats, and trade unionists. Arrests were made for speaking Polish in public, and in 1938 the Nazi-controlled police destroyed the Polish cultural centre. In June 1939, Polish students were expelled from the university. Also many other people seen as "undesirable" by Nazi Germany were sent to concentration camps. A network of concentration camps and forced labour camps was established around Breslau to serve industrial concerns, including FAMO, Junkers, and Krupp. Tens of thousand of forced laborers were imprisoned there. The last big event organized by the National Socialist League of the Reich for Physical Exercise, called Deutsches Turn-und-Sportfest (Gym and Sports Festivities), took place in Breslau from 26 to 31 July 1938. The Sportsfest was held to commemorate the 125th anniversary of the German Wars of Liberation against Napoleon's invasion. Second World War During the invasion of Poland, which started World War II, in September 1939, the Germans carried out mass arrests of local Polish activists and banned Polish organizations, and the city was made the headquarters of the southern district of the Selbstschutz, whose task was to persecute Poles. For