At the intersection of legend, tradition, and history stands the Basilica di Sant'Eustorgio. The foundation of this 4th century basilica is built upon the spot where, according to tradition, the apostle Barnabas baptized the first Christians in Milan. Eustorgio I, the city bishop from 344 AD, had the church built to house the relics of the Three Kings; legend has it that the animals pulling the cart of relics reached the spot and refused to continue. It may also coincide with a cemetery of early Christians martyred prior to the Edict of Milan. Whatever lies beneath it, today the church is filled with works by Lombard artists from the 13th to the 15th centuries. The main attraction, however, is the Cappella Portinari next door, built in the mid-1400s, and the earliest true Renaissance work in the city. It is a striking combination of classical forms and typical Lombard fresco decoration, and houses the intricate Ark of St Peter Martyr.