Originally, where the church of San Salvatore stands today, there was a Roman house with attached baths.
Probably, it was an offshoot of the larger baths, which according to the testimony of the historian Francesco Angeloni, were to be found precisely in that area. However, other suppositions surround the place in mystery: there are those who believe it was mausoleum to start with , who a baptistery, who an oratory, and then - lastly- who a pagan temple dedicated to the sun. In fact, art historians are particularly attracted by the mystery constituted by the unusual architectural construction system, which combines a rectangular apse with a round presbytery. A combination which makes the date uncertain as well as the original function of the building.
Fewer doubts, even if substantiated by some uncertanties in historical documents of the period, about the fact that in the 8th century it was the oratory connected to the church of San Pietro, and, according to some interpretations of original sources, it was precisely at San Salvatore that a peace treaty was signed between Pope Zaccaria and the Lumbard King Liutprando.
The only doubt that remains is that concerning the existence of a church dedicated to San Pietro in a place so different from the city centre. It stood close to the castle of Perticara, and also in the San Valentino area where Pope Zaccaria and Liutprando met. The church of Perticara also had as outbuilding an oratory called San Salvatore.
The fact that it may or may not have been the site where the contract was signed, however, does not change the importance of the little Romanic style church which stands in the heart of the old town centre, which contains several significant Umbrian Romanic elements and which was extended in 1100 with the addition of a small nave. On the inside some interesting finds together with frescos of indoubted attraction.