Originally oriented towards an eastern apse, as was common with paleochristian churches, some state it was the first cathedral in the town.
It was affiliated with a benedictine monastery, and was visited by St. Peter Damian while en route to die in the hermitage of Gamogna for the winter of 1072.
The interior was rebuilt and expanded starting in 1655, reversing the orientation, and adding a portico the entrance.
Built in the 9th century using likely Ancient Roman spolia, the unclad brick construction rises from a solid base but sports two rows of trifora windows.
Prior to 1944, the top was had a pointed spire and less windows, but damaged by gunnery, it was reconstructed to reflect a gothic decoration.