The Bishopric of Chur
The early Middle Ages (5th-10th centuries) are one of the crucial stages in the history of Raetia, a phase of the creation of the High Medieval Raetia Curiensis (Churrätien) and late Medieval and modern Graubünden. The transition from Roman rule to the Middle Ages was a long process in which political structures, social, economic and linguistic-ethnic developments, the ecclesiastical and cultural situation and geographical orientation fundamentally changed.
Since the first half of the 4th century, the Roman province of Raetia was divided into the provinces of Raetia prima and Raetia seconda. Raetia prima was the western province, Raetia seconda the eastern province. Raetia included the valleys of the Vorder- and Hinterrhein and the Engadine. In the north, the High Rhine and Lake Constance formed the border. In the west, the border ran from Stein am Rhein to Pfyn, over the rivers Glärnisch and Clariden to the Gotthard massif. In the south, the watershed between the Inn and the Rhine on the one hand, and Mera and Adda on the other formed the border.
In late antiquity (after 300 A.D.) Raetia was a northern periphery of the Roman Empire, in the early Middle Ages (6th-7th centuries ) a southern periphery of the Merovingian Frankish Empire, in the Carolingian period (8th-9th centuries) a periphery that fluctuated between Italy and the northern Alps, and later (10th century) a southwestern periphery of the eastern Franconian-German Empire. At the same time, however, Raetia has always been a transit country in the central Alps. Raetia was therefore both a peripheral and a transitional location. It explains its very significant political and strategic importance (the transit location and passes Julier, Septimer, Lukmanier and Splügen), but at the same time also its relative independence (the peripheral area).
The diocese of Chur played an essential role in this process. In the year 451, the bishop of Chur is mentioned for the first time. Milan was the archbishopric until 829, afterwards the archbishopric of Mainz. This change shows the geographical and political importance. (Source: R. Kaiser, Churrätien im frühen Mittelalter, Basel 2008).