Un diploma imperiale e tre carte vescovili. Le origini e i primi sviluppi dei possedimenti della cattedrale bobbiese: una rilettura

Three mills along the Bobbio torrent and as many mansi; a small vineyard and a few similarly small lands, among which were nine sortes. But above all, a curtis with a chapel and a number (of unspecified) dependencies of men and immovables. This was the original endowment of Bobbio’s episcopal mensa, roughly ten years after the foundation of the diocese. The setting is illustrated by a significant document: a diploma granted on 23 October 1027 by emperor Conrad II, who was also the founder of the new bishopric’s documentary tradition. In fact, the two previous documents, with which it is said that the second and third bishop of Bobbio had donated those same properties which the emperor would merely confirm, have not survived. These possessions had been detached from the mensa of the monastery of Saint Columbanus, an institution with which the newly-established diocese of Bobbio entertained a symbiotic yet ambiguous relationship for a few years. But the transfer of the aforementioned res must have been far from painless, and certainly not devoid of opposing claims, at least for what concerns the most copious part of the patrimony; nor was its possession on a long-term basis. Through a reappraisal of the most ancient documents and an examination of unedited archival material, this paper intends to furnish a reconstruction of these conflicting dynamics and of their impact on the definition of the patrimonial framework of the bishopric and of Bobbio’s cathedral chapter. These two organisms were respectively the author and beneficiary of a carefully-planned (and successful) documentary strategy founded on an underhanded falsification activity.