The Silesia region was part of the Prussian realm since 1740 and established as an official province in 1815, then became part of the German Empire in 1871. In 1919, as part of the Free State of Prussia within Weimar Germany, Silesia was divided into the provinces of Upper Silesia and Lower Silesia. Silesia was reunified briefly from 1938 to 1941 as a province of Nazi Germany before being divided back into Upper Silesia and Lower Silesia.