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. The site had a pre-Christian cemetery. 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. The abbey however fell into disuse and ruin, leaving behind only this church. The structure has been refurbished over the centuries.
The church houses a number of artworks including a detached fresco derived from the church of San Francesco. The church has paintings by Simonelli, Feliciano Mangieri and Nicola Peccheneda. A stone portal, attributed to Melchiorre da Montalbano, consists of flanking column-pilasters with bas-reliefs of bishops. In a niche above the portal is a half-figure bust of San Stefano.[2] The bronze doors (1699) are by Antonio Masini.[3]
Every August 23, a dressed icon of the patron of the town is carried in procession to the church.
