Since 1986 Gravina Cathedral has served as a co-cathedral of the Diocese of Altamura-Gravina-Acquaviva delle Fonti. It was built here at the end of the 11th century by Humphrey of Hauteville, Count of Apulia and Calabria, and thus lord of the town. This church was destroyed in the years 1447-1456 by a fire followed by an earthquake, after being refurbished in a Renaissance-Romanesque style. Of the original church only a few Byzantine capitals and frescoes remain. The present cathedral was built in the thirty years following, under the supervision of the bishop Matteo d'Aquino.
The main façade has a large rose window. The altarpieces are made from 17th-century intarsia with polychrome marble and mother of pearl. The ceiling has framed canvases. The church has an altarpiece carved in Bitonto stone (1468) by Guido da Guida. There is a San Michele (1538) carved in mazzaro, a local stone, and attributed to Stefano da Putignano. Along the north nave is a Byzantine fresco of the Madonna del Piede. The oak choir-stalls were made in the 15th century and rebuilt by Bishop Antonio Maria Manzolio (1581-1593).
The adjacent sacristy has a ceiling refurbished by bishop Manzolio, and elaborate presses. The bell-tower was built from a Norman watch tower.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.