The Principality of Erfurt (Fürstentum Erfurt) existed from 1806 to 1814 and included Erfurt and the surrounding land, including the Grafschaft Blankenhain.
Principality of Bulgaria | Erfurt | Principality of Ansbach | Principality of Lüneburg | Principality of Auersperg | Principality of Polotsk | Principality of Orange | Principality of Yaroslavl | Principality of Pereyaslavl | Principality of Calenberg | Principality of Lippe | Principality of Grubenhagen | Principality of Sealand | Principality of Piombino | Principality of Kiev | Principality of Catalonia | Principality of Anhalt-Zerbst | Principality of Zeta | Principality of Transylvania | Principality of Lichtenberg | Principality of Hungary | Principality of Halberstadt | Principality of Brunswick-Wolfenbüttel | FC Rot-Weiß Erfurt | Tabasaran Principality | Serbian Grand Principality | Principality of Valona | Principality of Ryazan | Principality of Reuss-Greiz | Principality of Reuss |