The original cathedral was dedicated to Saints Gervasius and Protasius before being rebuilt in the early ninth century by Bishop Jerome.

The apse and transept at the west end are the remains of a Romanesque church, built in the 11th century,[3] on the Carolingian foundations.

After the building suffered a series of fires in the 13th century, the Gothic nave and eastern apse were added to the still standing Romanesque parts.

The gothic nave and chevet were seriously damaged by bombing in July 1944 but later restored.

The cathedral preserves a polychrome oak triumphal cross dating from about 1200.