Basse Œuvre

It is the western end of a much longer church which had been Beauvais's cathedral, and was built in the form of a Roman basilica, a style which still characterized the Carolingian era.

The Basse Œuvre was built in the second half of the tenth century, and dedicated to St. Peter, the Virgin and St. John the Baptist.

However, Emile Shami, based on another anonymous manuscript source of the 17th century, suggested a date in the time of Bishop Hugh, predecessor of Hervé.

The north side was free from restoration, and overlooks the cloister of the bishopric, whose west wing is dated to the eleventh century.

Excavations showed a rebuilding of the facade of the Basse Œuvre and additions resulting from fires in the eleventh century.