Mainz

Mainz lies on the left bank of the Rhine opposite the mouth of the Main, where the Romans founded Mogontiacum and where the archbishop became the primate of Germany and an elector of the Empire. Its golden age began in 1244, when it became a free city; in 1254 its burghers founded the Rhenish League of Cities, and trade and crafts flourished under the league's shelter. The cathedral of Saint Martin dominated the city, which lived in a constant balance of power with its archbishop.

From 1328 conflict with the archbishop eroded the freedoms of the burghers. In the Mainz Diocesan Feud the townspeople sided with Archbishop Diether of Isenburg; in 1462 his rival Adolf of Nassau stormed the city, took away all of its privileges, and ended its time as a free city. Mainz became the archbishops' residence and a city of nobility and clergy. Around 1450 Johannes Gutenberg developed printing with movable type here, and the press carried the Gutenberg Bible's craft across Europe; Diether founded the university in 1477.

The Reformation made some headway, but the cathedral chapter twice chose Catholic archbishops, and until 1802 no Protestant congregation was allowed, apart from the garrison. In the Thirty Years' War Swedish troops took the fortress city without a fight, and an archbishop restored it afterwards. French armies took Mainz in 1792; the short-lived Republic of Mainz of 1793 ended in a Prussian siege, and in 1798 the city became part of France.