 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.As the burial areas grew around the remains of Gennaro so did underground places of worship for the growing Christian faith.An early example of religious use of the catacombs is the Basilica of Agrippinus dating to the fourth century.