Polish-speaking territories of Lower and Middle Silesia, commonly called the Polish side until the end of the 19th century, were mostly Germanized in the 18th and 19th centuries, except for some areas along the northeastern frontier. Modern history In 1742, most of Silesia was seized in the War of the Austrian Succession by King Frederick the Great of Prussia, who named himself a 'Piast prince' (he was actually a remote descendant) in his first declaration. The remainder of Silesia, known as Cieszyn Silesia, remained in the Austrian Empire. The Prussian part of Silesia constituted the Province of Silesia until 1918. Later, the province was split into the Prussian provinces of Upper and Lower Silesia. Owing to the development of education, a rebirth of Polish culture took place in the second half of the 1800s in Silesia, which was connected with the emergence of a Polish national movement of a clearly Catholic character. At the beginning of the twentieth century, the fact that Silesians were part of the Polish nation was not questioned. The language and culture of the self-declared Polish Silesians were put under the pressure of the Prussian Kulturkampf policies, which attempted to Germanize them in culture and language. The process of Germanisation was never completely successful. The cultural distance of Upper Silesians from the German population resulted in the development of Polish national awareness at the turn of the nineteenth and twentieth centuries, culminating in the pro-Polish movements at the end of World War I. After the Silesian Uprisings, the eastern minor, but richer, part of Upper Silesia became part of the newly restored Poland; most of the land that had been ruled by the Habsburgs following the 1742 war went to Czechoslovakia, while Lower Silesia and most of Upper Silesia remained in Germany. The ethnic situation of the region became more complex as the division of Upper Silesia into Polish and German parts led to ethnic polarization. The people that lived in the western part of Upper Silesia were subject to a strong German Ostsiedlung, where those living in the eastern part of Silesia started to identify with the Polish culture and statehood. World War II and its aftermath amplified this polarization. Three groups took shape within the Silesian population. The Polish-speaking group was the largest, while the German-speaking group, which primarily lived in central Silesia, was noticeably smaller. A third group supported separatism and an independent