For almost 1000 years (since 739) the Passau cathedral used to be the episcopal church of the largest diocese of the Holy Roman Empire of German Nation. The diocese Passau reached its largest expanse when it streched from the mouth of river Isar to Hungary, and from the foothills of the Alps to the Bohemian-Moravian border in the north. Between 1783 and 1785, emperor Joseph II separated the Austrian part of the diocese (almost sixth-seventh of the entire district) from the German part. Due to this, the diocese Passau became one of the smallest in Germany. That explains the comparatively large size of the cathedral, which is an eye-catcher in the small town of Passau.
Religious - Christianity
The former diocese of Passau played an important role in the Christianization of the regions east of the Danube. Since 999, the bishops also took care of all secular affairs as well. In 1217 Passau became the chief monestary and therefore also the bishop's domicile.
The St. Stephan cathedral was built on the highest elevation of the Old Town (13 m above the Danube and 303 m above sea level) between the Danube and river Inn. Its length of 102 m and 33,5 m width is complemented by the 69 m high pinnacle of the cupola. Hence it is one of the biggest cathedrals with the largest baroque interior north of the Alps.