 After an official ceremony presided over by the bishop Luigi Pallavicini, and in the presence of Charles Emmanuel I, Duke of Savoy, the church was recognized as a "chiesa-cattedrale".In 1649, judging the building to be too small, Bishop Didier Palletis commissioned the architect Jean-André Guibert to produce a structure more in keeping with the importance of the city.The construction of a new cathedral (the current main building) took place between 1650 and 1865.