 In May 1435 Bishop Enrico Rampini di Sant'Allosio presided over a synod held in the church of S. Domenico in Tortona.A diocesan synod was held in 1595 by Bishop Maffeo Gambara (1592–1612).A synod was held by Bishop Cosimo Dossena (1612–1620) on 25 October 1615.