The ARCHBISHOPRIC OF MAINZ, one of the seven electorates of the Holy Roman Empire, became a powerful state during the middle ages and retained some of its importance until the dissolution of the empire in 1806. Its archbishop was president of the electoral college, arch-chancellor of the empire and primate of Germany. Its origin dates back to 747, when the city of Mainz was made the seat of an archbishop, and a succession of able and ambitious prelates, obtaining lands and privileges from emperors and others, made of the district under their rule a strong and vigorous state. Among these men were Hatto I. (d. 913), Siegfried III. of Eppstein (d. 1249), Gerhard of Eppstein (d. 1305), and Albert of Brandenburg (d. 1545), all of whom played important parts in the history of Germany. There were several violent contests between rivals anxious to secure so splendid a position as the electorate, and the pretensions of the archbishops occasionally moved the citizens of Mainz to revolt. The lands of the electorate lay around Mainz, and were on both banks of the Rhine; their area at the time of the French Revolution was about 3200 sq. m. The last elector was Karl Theodor von Dalberg. The archbishopric was secularized in 1803, two years after the lands on the left bank of the Rhine had been seized by France. Some of those on the right bank of the river were given to Prussia and to Hesse; others were formed into a grand duchy for Dalberg. The archbishopric itself was transferred to Regensburg. For the history of the electorate see the _Scriptores rerum moguntiacarum_, edited by G. C. Joannis (Frankfort, 1722-1727); Schunk, _Beiträge zur Mainzer Geschichte_ (Frankfort, 1788-1791); Hennes, _Die Erzbischöfe von Mainz_ (Mainz, 1879); Ph. Jaffé, _Monumenta moguntina_ (Berlin, 1866), and J. F. Böhmer and C. Will, _Regesta archiepiscoporum moguntinensium_ (Innsbruck, 1877-1886).