its elevation to an archdiocese in 780/82. The first bishops before the 4th century have legendary names, beginning with Crescens. The first verifiable Bishop of Mainz was Martinus in 343. The ecclesiastical and secular importance of Mainz dates from the accession of St. Boniface to the see in 747. Boniface was previously an archbishop, but the honor did not immediately devolve upon the see itself until his successor Lullus. In 1802, Mainz lost its archiepiscopal character. In the secularizations that accompanied the Reichsdeputationshauptschluss ("German mediatization") of 1803, the seat of the elector, Karl Theodor von Dalberg, was 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 Prussia. Dalberg retained the Aschaffenburg area however, and when the Holy Roman Empire finally came to an end in 1806, this became the core of Dalberg's new Grand Duchy of Frankfurt. Dalberg resigned in 1813 and in 1815 the Congress of Vienna divided his territories between the King of Bavaria, the Elector of Hesse, the Grand Duke of Hesse-Darmstadt and the Free City of Frankfurt. The modern Diocese of Mainz was founded in 1802, within the territory of France and 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 mediæval tradition of the cathedral chapter electing a successor to the bishop. Bishops and archbishops Bishops of Moguntiacum, 80–745 Crescens c. 80–103 Marinus c. 103–109 St. Crescentius c. 109–127 Cyriacus c. 127–141 Hilarius c. 141–161 Martin I c. 161–175 Celsus c. 175–197 Lucius c. 197–207 Gotthard c. 207–222 Sophron c. 222–230 Heriger I c. 230–234 Ruther c. 234–254 Avitus c. 254–276 Ignatius c. 276–289 Dionysius c. 289–309 Ruprecht I c. 309–321 Adalhard c. 320s Lucius Annaeus c. 330s Martin II c. 330s – c. 360s Sidonius I c. late 360s – c. 386 Sigismund c. 386 – c. 392 Theonistus or Thaumastus Maximus Lupold c. 392 – c. 409 Nicetas c. 409 – c. 417 Marianus c. 417 – c. 427 Aureus c. 427 – c. 443 Eutropius c. 443 – c. 467 Adalbald Nather Adalbert (I) Lantfried Sidonius II ? – c. 589 Siegbert I c. 589–610 Ludegast c. 610–615 Rudwald c. 615 Lubald ? fl. c. 625 Rigibert 708-724 Gerold 724–743