During excavations in and around the so-called "Chiesa rossa" (S. Maria alla fonte), situated on the eastern tow-path of the Naviglio, ten distinct phases were identified. The earliest remains (phase I) are traces of a wooden structure dating to the early empire, followed in phase II by a rectangular structure with a brick floor beneath which are the remains of a "channel" heating system (1st -3rd centuries A.D.). Later, in phase III, this structure was divided into two rooms and a large apsidal hall was built to to the east. Phase IV is attested by the construction of a rectangular narthex linked to a cruciform room with an apse, a structure which had already been identified in 1966. The new rooms are connected to the earlier ones and have opus sectile pavement throughout, with the exception of the apse which is paved in mosaic, giving them a date of the 4th - 6th centuries A.D. The late antique structures continue in use during phase V (6th -7th centuries A.D.) and a new room was added. Between the 7th - 8th centuries A.D. (phase VI) partial demolition of the structures occurs, with the exception of the cruciform room which clearly assumes a religious function as attested by the numerous burials which surround it. In the carolingian period (phase VII) a portico is added to the front of this the narthex and its funerary function increases in importance, a phenomenon which continues throughout the 9th-13th centuries (phases VIII-IX). In phase X a romanesque church with a large cemetery to its north is built. (Anna Ceresa Mori)