Prussia
This was Prussia's high moment. The economic and political future looked good. But after 99 days, in 1888, the state had a new leader, Kaiser Wilhelm II. He fired Bismarck, who lost his job in 1890, and Wilhelm II started a new foreign policy.  He made the army bigger, and the navy much bigger, and he took risks. This is part of why Germany entered World War I. When the Germans and their allies lost that war, the Prussian Junkers lost power.  The Prussian king and the other German kings had to leave.  Germany became the Weimar Republic. In 1919, the Treaty of Versailles re-created the Polish state, and Prussia had to give up much of its land.  The Polish Corridor was split between East Prussia and Germany.