For centuries Upper Silesia was a borderland between Polish and German national ecumenes. As a political periphery, Upper Silesia became the key economic region in the 19th century. After World War II this region became a part of Poland and was subjected to various forms of political activity. The paper discusses many general aspects of this politics, for example population migrations, expulsion of the Germans, 'de-germanization', verification, depreciation of the Silesian and German culture, prohibition of school instruction in German or reforms of the administrative division. Further on the authors discuss key processes of resistance and areas of conflict which supported the survival of the region of Upper Silesia and its regional culture. At present the processes of assimilation and establishing internal homogeneity of the culture of Upper Silesia , although different in nature, are still visible in Poland.