moved to Regensburg, and the electorate lost its left bank territories to France, its right bank areas along the Main below Frankfurt to Hesse-Darmstadt and the Nassau princes, and Eichsfeld and Erfurt to the Kingdom of Prussia. Dalberg retained the Aschaffenburg area as the Principality of Aschaffenburg. In 1810 Dalberg merged Aschaffenburg, Frankfurt, Wetzlar, Hanau, and Fulda, to form the new Grand Duchy of Frankfurt in 1810. Dalberg resigned in 1813 and in 1815 the Congress of Vienna divided his territories between the Kingdom of Bavaria, the Electorate of Hesse-Kassel (or Hesse-Cassel), the Grand Duchy of Hesse and the Free City of Frankfurt. The modern Roman Catholic Diocese of Mainz was founded in 1802 when Mainz lost its archdiocese status and its territory west of the Rhine River became a mere diocese within the territory of France. In 1814 its jurisdiction was extended over the territory of Hesse-Darmstadt. Since then it has had two cardinals and via various concordats was allowed to retain the medieval tradition of the cathedral chapter electing a successor to the bishop. See also Electorate of Cologne Electorate of Trier References External links of the modern Diocese Map of the Archbishopric of Mainz in 1789 780 establishments 1803 disestablishments in the Holy Roman Empire Dioceses established in the 8th century Electoral Rhenish Circle Electorates of the Holy Roman Empire Former states and territories of Bavaria Former states and territories of Hesse Former states and territories of Rhineland-Palatinate History of Catholicism in Germany Electorate Prince-bishoprics of the Holy Roman Empire in Germany Former monarchies of Europe