Principality of Erfurt

The Principality of Erfurt was a small state in modern Thuringia, Germany, that existed from 1807 to 1814, comprising the modern city of Erfurt and the surrounding land. It was subordinate directly to Napoleon, the Emperor of the French, rather than being a part of the Confederation of the Rhine. After nearly 3 months of siege, the city fell to Prussian, Austrian and Russian forces. Having mainly been Prussian territory before the Napoleonic Wars, most of the lands were restored to Prussia by the Congress of Vienna.

In the wake of the French Revolutionary Wars and the Treaty of Lunéville, the Holy Roman Empire underwent a process of substantial territorial reorganisation known as the German mediatization, under which Erfurt, since the 10th century a subject of the Electorate and Archbishopric of Mainz, was transferred to the Kingdom of Prussia, to compensate for territories Prussia lost to France on the Left Bank of the Rhine.

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