The article analyses the socio-political situation in Prussian Upper Silesia (administratively the Opole region/ plebiscite area) in the period of autumn 1918. - May 1922. The region belonged to the typical regions of Central and Eastern Europe with a mixed national and religious population and loyalties running sometimes backwards from the ethnic equipment. Although statistically it was dominated by a Slavic/Polish-speaking population, politically it was dominated by the German Catholic Centre Party before the war. It was distinguished by its economic potential, as the Upper Silesian Industrial District was one of the largest centers of heavy industry in Europe. The plebiscite established by the Treaty of Versailles, which was to decide on its nationality, took place on March 20, 1921. After an armed attempt at a fait accompli by the Polish side, the plebiscite area was finally divided on a national basis by a decision of the Council of Ambassadors.