[1] The church is thought to have been erected at the site of a pagan Serapeum, and that some of the capitals of the columns are spolia from such a temple.
Documents maintain the Abbey of Santo Stefano was erected here under the patronage of a Count Osmondo during the rule of the Norman Robert Guiscard in the region.
The abbey putatively held the relics of San Gianuario, a 4th-century bishop martyred nearby by Diocletian.
A stone portal, attributed to Melchiorre da Montalbano, consists of flanking column-pilasters with bas-reliefs of bishops.
[3] Every August 23, a dressed icon of the patron of the town is carried in procession to the church.