In 1748, Pope Benedetto XIV erected the Bishop’s Palace of Pinerolo and the Cathedral of the diocese in the Chiesa di San Donato, declaring it the most worthy of all of the churches in the city to adorn itself with this title. The church therefore became a cathedral, assuming the title of Santa Maria Assunta and its co-patrons San Donato and San Maurizio. The first church dedicated to San Donato seems to date back to the 11th century when the Borgo Piano di Pinerolo, outside of the city walls, became the residential area and base for commercial activity, for fairs and for markets travelling across the valleys towards Torino and from Piemonte towards Savoia. In the course of the 15th century, the structure underwent a long series of transformations: its first major expansion dates back to 1442, but the decisive modifications were made towards the end of the 15th century (1495-1507). The responsibility for designing the reconstruction of the church was placed in the hands of the ‘massari’ Antonio Peruca and Antonio Botalli; the new church, which was not yet complete, was consecrated in 1507. The internal decoration was concluded in 1568, and 16 years later, at the end of the extension works, the lateral chapels were also concluded. Only in 1766, though, was there any record of work taking place in the choir and presbytery. The first interventions, designed by the engineer Ghigliani, were actuated after 1811 due to the damage caused by the earthquake of 1808. At the end of the 19th century, a second and important phase of restoration commenced which lasted until 1903. The interior decoration of the Cathedral, with its magnificent pictorial cycle which represents events and personalities of the Old and New Testament was carried out between 1887 and 1911.
