 The Duchy of Crossen was inherited by the Margraviate of Brandenburg in 1476, and with the renunciation of King Ferdinand I and the estates of Bohemia in 1538, became an integral part of Brandenburg.In 1742, most of Silesia was seized by King Frederick the Great of Prussia in the War of the Austrian Succession, eventually becoming the Prussian Province of Silesia in 1815; consequently, Silesia became part of the German Empire when it was proclaimed in 1871.After World War I, a part of Silesia, Upper Silesia, was contested by Germany and the newly independent Second Polish Republic.