The Polish-speaking territories of Lower and Middle Silesia, commonly described until the end of the 19th century as the Polish side, were mostly Germanized in the 18th and 19th centuries, except for some areas along the northeastern frontier.[15][16] The province came under the control of Kingdom of Bohemia in the 14th century and was briefly under Hungarian rule in the 15th century. Silesia passed to the Habsburg Monarchy of Austria in 1526, and Prussia's Frederick the Great conquered most of it in 1742. A part of Upper Silesia became part of Poland after World War I, but the bulk of Silesia formed part of the post-1945 Recovered Territories.