Drawing on different disciplinary and historiographic traditions, the volume offers a series of summaries and thematic insights, functional to contextualising the peculiar case of the episcopate of Bobbio, founded in 1014 in the Piacenza Apennines as a development of the famous monastery of San Colombano. The considerable documentary source available thanks to the recent reorganization of the diocesan archives, which made it possible to illustrate the cathedral library as well, required an overall presentation and specific attention to the constitutive acts of the new institution. The deepening of the historical context, within which the subsequent diocesan story unfolds, was conducted in relationship with the monastery and with a selection of the nearby cities. The analysis of the settlement dynamics of the Bobbian center and of the structural developments of the church and of the episcopal complex are counterpointed by both in-depth analyses aimed at the organization of the territory, captured in its civil, religious, welfare articulations, and treatments of cultural and liturgical components that animate this Church.