Rib vaults in 12th-century religious architecture in the North-West of Italy

Romanesque architecture in North-West Italy was mainly characterized by the use of ribbed vaults, with diagonally reinforced arches used in some important monastic sites where the architectural choices became more specific and accomplished. The diocese of Vercelli seems to be the area where rib vaults were developed; some examples are the church of San Bernardo in Vercelli and the solutions implemented in the Badia of Dulzago and partly in San Nazzaro Sesia. Novarese architecture underwent a considerable period of experimentation during the first quarter of the 12^th century: Novara cathedral, consecrated in 1132 (and destroyed in the middle of the 19^th century), is the most evident and relevant example of pillars with diagonal lesenes, an alternate system of support, and ribbed vaults with diagonally reinforced arches. Similar solutions were also adopted in Vercelli cathedral, which also no longer exists. To trace the technical and architectural changes in rib vaulting, it was necessary to investigate the main Cistercian sites opened during the 12^th century: in particular those located in Lucedio, Tiglieto, Staffarda and Casanova, and in Rivalta Scrivia, and also Canonical of Vezzolano, where the first forms of experimentation of ribbed vaults, especially in the sections and laying of ribs, reached full maturity.