The primitive core of the Church of St Euphemia dates back to before the year 1000.
It was only after 1100, however, that the temple found its final settlement and importance. The discovery of the remains of the martyr Euphemia triggered the decisive process to begin the renovation of the building, which was then officiated by the cloistered canons of St. Augustine and consecrated in 1108.
A monastery remained annexed to the church complex for centuries, which in 1491 was handed over to the Augustinian regular canons and in the 17th century to the Canons of St. Salvatore, who managed it until its suppression in 1805 (important structures of the monastic context remain). The slender portico, resting on pillars adorned with precious Romanesque capitals, dates back to those years.
The interior has three naves, with cross vaults, cruciform pillars and semicircular apses. A piece of mosaic with a figure of a dragon (12th century) is preserved here, part of the ancient mosaic floor that was destroyed during the 17th century when the church gallery was lowered (1652) and the choir was built (1658).
The paintings include an oil painting on panel attributed to Cesare Cesariano from 1512, depicting the Madonna with the Infant Jesus and four saints, three of whom are Euphemia, Victor and Sosthenes.
Terracotta predominates throughout the building.
According to tradition, Bishop Aldo wanted to be buried in this church, but his remains were never found. During excavations, however, the remains of St. Euphemia resurfaced.
