necessary co-operations, as well as equal rights for all inhabitants in both parts of Upper Silesia, were all fixed by the German-Polish Accord on East Silesia, signed in Geneva on 15 May 1922. On 20 June the Weimar Republic ceded, de facto, the eastern parts of Upper Silesia, becoming part of the Silesian Voivodeship of the Second Polish Republic. Within Weimar Germany, the Prussian Province of Silesia was divided into the provinces of Upper Silesia and Lower Silesia The territory remaining in Prussian Upper Silesia was administered within the Oppeln Region and — according to Polish sources — had 530,000 Poles within it. Nazi Germany After the Nazis' takeover in Germany, anti-Semitic laws were also introduced in German Upper Silesia, against the German-Polish Accord on East Silesia of 1922. Among other stipulations, according to the treaty each contractual party guaranteed in its respective part of Upper Silesia equal civil rights for all the inhabitants. The German Upper Silesian Franz Bernheim succeeded in convincing the League of Nations to force Nazi Germany to abide by the Accord, by filing the Bernheim petition. Accordingly, in September 1933 the Reich's Nazi government suspended in German Upper Silesia all anti-Semitic discrimination laws already imposed and excepted the province from all new such future decrees, until the Accord expired in May 1937. The Province of Upper Silesia was joined to Lower Silesia to form the Province of Silesia in 1938. World War II After the invasion of Poland in 1939, Polish Upper Silesia, including the Polish industrial city of Kattowitz, was directly annexed into the Province of Silesia. This annexed territory, also known as East Upper Silesia (Ostoberschlesien), became part of the new Regierungsbezirk Kattowitz. German occupation forces began a policy of repression against the Polish population of eastern Upper Silesia, which started as early as September 1939 based on lists made before the war that pointed out Poles active in social and political life. A second wave of arrests happened during October and November in Intelligenzaktion Schlesien, aimed against Polish intellectuals, many of whom perished in prison camps. A third wave of arrests came in April and May 1940 during the AB Aktion. In Katowice, according to the historian Czesław Madajczyk, one of the harshests centres of oppression was the prison on Mikołowska street where people were reported to be murdered by Germans through the use of guillotine. A prison and penal camp were