Bitonto Cathedral, dedicated to Saint Mary, was the seat of the small Bishopric of Bitonto from the bishopric's foundation, believed to be in the 8th century, until 1818, when it was combined with the neighbouring Diocese of Ruvo to form the Diocese of Ruvo e Bitonto. This was separated again in 1982, and the Diocese of Bitonto, with Bitonto Cathedral as its seat, was briefly revived, but was combined with the Archdiocese of Bari in 1986 to form the Archdiocese of Bari-Bitonto, in which Bitonto Cathedral is now a co-cathedral.
The remains of a palaeochristian church, which predates by some centuries the establishment of the bishopric, have been discovered underneath the present building.
The existing church however is a Romanesque building of the late 11th-12th centuries, influenced by the Basilica of San Nicola in Bari. The west front is divided into three parts and has three portals (the central one of which is sculpted with plant motifs and scenes from the Old Testament), four mullioned windows and a rose window flanked by sculptures of animals supported by small columns. The interior has a nave and two aisles, and is also notable for its sculpture. The main artwork is the marble ambo, a combined pulpit and lectern, of 1229, a masterpiece of medieval Apulian stonecarving. In the crypt is a tile of a griffin, a survival from the predecessor church building.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.