The origin of the church is very old; a building dedicated to St. Peter was erected there in the early 5th century already, by bishop Achilleo, who had moved St. Peter’s chains to Spoleto.
The church was then rebuilt in the 12th-13th centuries, but in the early 14th century it was heavily damaged because of the disputes between Guelphs and Ghibellines, causing immediate renewal that started in 1329 and dragged along until the early 15th century. A further renewal on the model of the cathedral took place in the late 17th century.
The façade almost integrally survived all interventions; it is one of the best samples of Romanesque in Umbria and is adorned by a very beautiful sculptural decoration (12th-13th cen), portraying religious scenes and allegories taken from ancient culture and Medieval bestiaries, reinterpreted in Christian key.

L’Umbria, Manuali per il territorio, Spoleto, Roma 1978