German Empire
The high command under Paul von Hindenburg and Erich Ludendorff increasingly controlled the country, but in October after the failed offensive in spring 1918, the German armies were in retreat, allies Austria-Hungary and the Ottoman Empire had collapsed, and Bulgaria had surrendered. The Empire collapsed in the November 1918 Revolution with the abdications of its monarchs. This left a postwar federal republic and a devastated and unsatisfied populace, which later led to the rise of Adolf Hitler and Nazism.
Perpetual Diet of Regensburg
The last action of the Diet, on 25 March 1803, was the passage of the German Mediatisation, which reorganized and secularized the Empire. Following the approval of that final constitutional document, the Diet never met again and its existence ended with the fall of the Empire in 1806.