The town of Castiglione Olona rose around the fifth century AC under the roman empire domain. Consequently, the Lombards entered and took possession of the village until the Castiglioni family became sole proprietor of the land around 1000 AC. The family engaged in many battles for the rule of the lands so they had walls built all around the village to protect themselves from enemies. Today only a small part of the walls near the fortress is visitable. In 1422, cardinal Branda Castiglioni obtained the permission to build the church of Collegiata thanks to the authorization from Pope Martin V so to properly enter the changes and ideals of the upcoming Renaissance period.