Some early Christian objects (lamps, bronze seals) are evidence of the existence of a Christian community in Pollenzo in the 5th century which settled around the church of San Vittore, built outside the Roman city, near the monumental necropolis of Piazza Vittorio Emanuele II. Archaeological excavations have unearthed among several burials that of a young woman of East Germanic origin (the so-called "Lady of Pollenzo"), which ends the use of the cemetery in the middle of the fifth century.
After the abandonment of the necropolis of Roman and late ancient age the area was occupied by stone and wooden buildings. The settlement, distributed around the early Christian church and probably equipped with houses for the military garrison, was enclosed by a wall, perhaps to be identified with the castrum Pollentinum mentioned by written sources.
Inside the amphitheatre, which was no longer used for events, wooden houses were built, they were later burnt and destroyed during the Greek Gothic War (535-552).
Pollenzo was never totally abandoned, as confirmed by modest houses and fragments of marble decoration (sec. VIII-IX), referable to the liturgical furnishings of the ancient parish church of San Vittore.
At the end of the 10th century the Abbey of San Pietro di Breme was given the "place" of  Pollenzo by Oddone, the son of the Marquis of Turin Arduino il Glabro. The monks built a new church there, named after Saint Peter, which became the centre of a large village. The excavations in the Carlo Alberto Agency have highlighted a large cemetery, with about eighty tombs dating from the tenth to the thirteenth century, and the contemporary town.
In 1292 the village was destroyed and the land previously occupied by the houses Antonio Porro built a "shelter" around 1380