The Cathedral was built by Geoffrey of Altavilla between the eleventh and twelfth centuries, on the previous church dedicated to St. Peter (now the crypt). In 1063, the Cathedral was expanded with the added of three naves with twelve pillars connected by arches, typical of the Romanesque style. Frederick II has buried here two of his wives. During the fifteenth century, the del Balzo family had made new interventions on the Cathedral, expanding the presbytery and building the Chapel of St. Richard (the "Big Chapel"), decorated with bas-reliefs depicting the life of the Saint. The building underwent further changes (with the addition of new chapels) until the nineteenth century, when was built the facade, work of Federico Santacroce, and the porch. The Crypt has great historical value: according to tradition, in 44 AD, St. Peter has celebrated a Mass of evangelization; in 537 it was buried St. Richard, in a stone sarcophagus with a canopy supported by columns. The Cathedral also preserves important works from the destroyed Benedictine convent (panel painting of the twelfth century, depicting the "Madonna of Andria", the ancient portal of the convent). The bell tower is set on a Lombard tower of the eighth century.