A magnificent example of the Lombard Romanesque style, this basilica with clean lines was founded in the 4C by St Ambrose to house the bodies of two martyrs, Gervasio and Proteo (preserved in a silver shrine in the crypt). It is preceded by a superb atrium, the arcades of which rest on fine capitals. Among the remarkable artworks, note the lovely Byzantine-Romanesque ambo (pulpit), the gold- and silver-plated altar front (a masterpiece dating from the 9C), and the beautiful 5C mosaics.