Since 1709, Conzano was annexed to the Duchy of Savoy, under direct control of the Casale Monferrato district before, the Marengo department during the Napoleonic occupation. The ruins of ancient medieval structure of the village castle was remodeled in the Franciscan convent building, now at the end of the 18th century, rebuilt to house destined to a rich Count named Carlo Vidua [https://web.archive.org/web/20060507012706/http://castelliaperti.it/ita/popup_castelli.lasso?id=996]; The villa, which is open to the public, is particularly known for its interior decorations in the Chinese manner.<br>