Introduction: the medieval background

During the early Middle Ages the eastern Alps comprised large swathes of territory assigned to ecclesiastical rulers who also enjoyed temporal sovereignty. The repeated involvement of the Holy Roman emperors in Italian politics, and therefore the need to defend communication routes between Germany and the peninsula, had led to the creation of the ecclesiastical principalities of Trent, Bressanone/Brixen and Aquileia, whose original function can be traced back to controlling stretches of the roads through the southern Alps.

Having been granted sovereign rights over the counties of Trent, Bolzano/Bozen, Venosta/Vinschgau and parts of the Val Pusteria/Pustertal between 1027 and 1034, the bishops of Trent and Bressanone/Brixen effectively controlled the roads that led south from the Resia and Brenner passes, or crossed the Val Pusteria/Pustertal to follow the line of the Roman road, the Claudia Augusta, on to the plains of the Veneto. Likewise, when the patriarch of Aquileia was granted the counties of Friuli, Istria and Carniola by the emperor in 1077 (albeit not permanently), a vast ecclesiastical dominion was formed to protect the roads over Monte Croce, in the Carnic Alps, and the Iron Road (the via vel strata Hungariorum), the best routes at the time for travellers heading for the Adriatic ports or for eastern Europe.