Prussia after WWI and the effects of the Versailles Treaty. (Weimar Republic) from wikipedia: (It had to cede virtually all territory belonging to the provinces of Posen and West Prussia to the newly created state of Poland and the League of Nations mandate of the Free City of Danzig. Smaller areas had been ceded to Belgium (East Cantons, formerly Rhineland), Czechoslovakia (Hlučín Region, formerly Silesia), Denmark (South Jutland, formerly Schleswig-Holstein), the League of Nations mandate of the Memel Territory (formerly East Prussia), Poland (eastern Upper Silesia, formerly Prov. of Silesia), and the Mandatory Saar (League of Nations) (formerly Rhineland).