The current church was built at the beginning of the XII century over the remains of a previous early Christian building, built around the V or VI century and restored after 793. The new church, in the Romanesque style, was built around 1110, re-utilising part of the previous construction material. After the earthquake of 1117, the perimeter walls of the apses were raised. At the end of the century the church was completed with the addition of the transept, the women’s gallery and cylindrical towers. The two different phases of construction (1110 and post-1117) are recognisable because of the difference between the lower wall, built with river rock arranged like a fish spine, alternated with rows of tuff and fired brick, and the upper wall, where only tuff and fired brick were utilised. But the beauty and suggestiveness of the building, created by the equilibrium of the individual architectural parts, the warm chromatics of the materials and the calibrated play of light through the narrow splay windows, were later destroyed by additions and remodelling.
Architecture and Art. The façade, which is on the left side, is pressed between two graduated towers, from which access was gained to the women’s galleries.
The red marble door, with sculpted decorations, is surmounted by a prostyle with elegant renaissance arches. The external face is built with bands of tuff and brick.
The plan is a Latin pentapses Benedictine cross, divided into two areas by the transept. Intimate and suggestive, the interior is divided into three naves concluding with three apses and a transept with two spans, terminating with a small apse, which has the same orientation as the larger ones. The presence of the women’s galleries, which are still intact, is rare and precious. They open on three sides along the upper floor of the smaller naves and the counter face: the women’s galleries are as large as the two lateral naves and face the altar above them, like a loggia.