Prussia
In 1945, the Soviet Union's army captured all of eastern and central Germany (and Berlin). Poland took everything east of the Oder-Neisse line, e.g. Silesia, Pomerania, eastern Brandenburg, and East Prussia. The Soviet Union took the northern third of East Prussia, including Königsberg, now Kaliningrad.  About ten million Germans had to run away from these areas. Polish and Russian people moved in in their place. Because of this, and because the Communists took control of land in the GDR, also called East Germany, the Junker and Prussia were finished.