Originally, there were three separate cemeteries, dedicated, respectively, to
Saint Gaudiosus (
San Gaudioso),
Saint Severus (
San Severo) and
St. Januarius (
San Gennaro). These
catacombs in Naples are different from their Roman counterparts in that they have more spacious passageways along two levels. The lower level is the oldest, going back to the 3rd-4th century and may actually be the site of an earlier pre-Christian cemetery later ceded to the new sect. It apparently became an important religious burial site only after the entombment there of Bishop
Agrippinus. The second level was the one expanded so as to encompass the other two adjacent cemeteries. The foundation of
San Gennaro extra Moenia is connected with the Catacombs of San Gennaro, the largest Christian catacomb complex in southern Italy. The first structure was probably the result of the fusion of two ancient burial sites, one from the 2nd century CE that contained the remains of
Saint Agrippinus of Naples, the first
patron saint of
Naples, and the site from the 4th century CE that contained the remains of
St. Januarius, the patron saint of the city. The site was consecrated to Gennaro (Januarius) in the fifth century on the occasion of the entombment there of his remains, which were later removed to the
Cathedral of Naples by
Bishop John IV (842-849) in the 9th century. == Types of burials ==