The Archbishopric of Mainz was a substantial ecclesiastical principality of the Holy Roman Emperor. It included lands near Mainz on the both the Left and Right Banks of the Rhine, as well as territory along the Main above Frankfurt (including the district of Aschaffenburg), and territory around Erfurt in Thuringia. The Archbishop was also, traditionally, one of the Imperial Electors and the Archchancellor of Germany. In the secularizations that accompanied the Reichsdeputationshauptschluss of 1803, the seat of the Archbishop-Elector, Karl Theodor von Dalberg, was moved to Regensburg, and the Archbishopric lost its Left Bank territories to France, its right bank areas along the Main below Frankfurt to Hesse-Darmstadt and the Nassau princes, and Erfurt to Prussia. The Archbishop retained the Aschaffenberg 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.

Since 1803, Mainz has not been the seat of an Archbishopric

Archbishops of Mainz, 745-1803

  • Bonifacius 745-755
  • Lullus 755-786
  • Richholf 787-813
  • Adolf 813-826
  • Odgar 826-847
  • Rhabanus Maurus 848-856
  • Karl 856-863
  • Ludbert 863-889
  • Sunderhold 889-891
  • Hatto I 891-913
  • Herigar 913-937
  • Friedrich 937-954
  • Wilhelm 954-968
  • Hatto II 968-970
  • Rudbrecht 970-975
  • Wilgis 975-1011
  • Erchenbald 1011-1021
  • Aribo 1021-1031
  • Bardo 1031-1051
  • Leutpold 1051-1059
  • Siegfried I 1060-1084
  • Wezilo 1084-1088
  • Rudhart 1088-1109
  • Adalbert I 1111-1137
  • Adalbert II von Saarbrücken 1138-1141
  • Markholf 1141-1142
  • Heinrich I 1142-1153
  • Arnold 1153-1160
  • Konrad I von Wittelsbach 1161-1165
  • Christian I 1165-1183
  • Konrad I von Wittelsbach (restored) 1183-1200
  • Lupold von Scheinfeld 1200-1208
  • Sigfried II von Eppenstein 1200-1230 (in opposition to 1208)
  • Sigfried III von Eppenstein 1230-1249
  • Christian III von Weissenau 1249-1251
  • Gerhard I von Daun-Kirberg 1251-1259
  • Werner II von Eppenstein 1260-1284
  • Heinrich II von Isny 1286-1288
  • Gerhard II von Eppenstein 1286-1305
  • Peter Aspelt 1306-1320
  • Matthias von Buchek 1321-1328
  • Heinrich III von Virneberg 1328-1337
  • Gerlach von Nassau 1346-1371
  • Johann I von Luxemburg-Ligny 1371-1373
  • Ludwig von Meissen 1374-1379
  • Adolf I von Nassau 1379-1390
  • Konrad II von Weinsberg 1390-1396
  • Johann II von Nassau 1396-1419
  • Joffrid von Leiningen 1396-1397 (in opposition)
  • Konrad III Wild- und Rheinsgraf zum Stein 1419-1434
  • Dietrich I 1434-1459
  • Dieter von Isenburg 1460-1461
  • Adolf III von Nassau 1461-1475
  • Dieter von Isenburg (restored) 1476-1482
  • Albert II 1482-1484
  • Bertold von Henneberg-Römhild 1484-1504
  • Jakob von Liebenstein 1504-1508
  • Uriel von Gemmingen 1508-1514
  • Albert III von Brandenburg 1514-1545
  • Sebastian von Heusenstamm 1545-1555
  • Daniel Brendel von Homburg 1555-1582
  • Wolfgang von Dalberg 1582-1601
  • Johann Adam von Bicken 1601-1604
  • Johann Schweikhard von Kronberg 1604-1626
  • Georg Friedrich von Greiffenklau 1626-1629
  • Anselm Casimir Wambold von Untadt 1629-1647
  • Johann Philipp von Schönborn 1647-1673
  • Lothar Friedrich von Metternich 1673-1675
  • Damian Hartrad von der Leyen 1675-1678
  • Karl Heinrich von Metternich 1679
  • Anselm Franz von Ingelheim 1679-1695
  • Lothar Franz von Schönborn 1695-1729
  • Franz Ludwig von Pfalz-Neuburg 1729-1732
  • Philipp Karl von Eltz 1732-1743
  • Johann Friedrich Karl von Ostein 1743-1763
  • Emmerich Josef von Briedbach 1763-1774
  • Friedrich Karl Josef von Erthal 1774-1802
  • Karl Theodor von Dalberg 1802-1803 (d.1817, Archbishop of Regensburg 1803-1810, Prince of Frankfurt 1806-1810, Grand Duke of Frankfurt 1810-1813)