In the period between 1439 and 1521 the coalition of Swiss rural communities and towns conquered eight districts in the alpine valleys along the St. Gotthardroute, which had been part of the Milanese duchy since its rise in the 14th century. The establishment of a new regime in this region was the result of a complex negotiation process, because the linguistic, legai, and political cultures of the new rulers and their subjects were fundamentally different. The paper focuses on a public notary of the Leventina valley named Pietro Pedruzzi, by observing his activity as a charter writer as well as a public official and as an intermediary between the conquerors and the local community members. he createci severa! new forms of documents combining elements of the notarial «instrumenta» and the sealed charters, which were functional both to the administration of the territories and to the representation of the new rulers' power.