The origins of Gesualdo Castle can be traced back to the Middle Ages during the Lombard conquests in southern Italy in the 7th century. It was founded either by the legendary Knight Sessualdo or by Radelchi, Prince of Benevento, as a defensive outpost. The first documented records date back to the 12th century under Norman rule, with William of Altavilla as the first lord. The castle gained importance during the Norman-Swabian era and became a prominent fortress in the region.
Carlo Gesualdo, a descendant of the Norman line, transformed the castle into a Renaissance-style mansion in the late 15th century. Over the centuries, the castle suffered damage and looting during various conflicts, including the Franco-Spanish War and the arrival of French troops in 1799. It underwent significant renovations in the 19th century and was designated as a site of historical and artistic value in 1913. The castle was severely damaged in the 1980 Irpinia earthquake and has undergone ongoing restoration efforts. Currently, a portion of the castle is open to the public, and future plans include establishing a polyphony education high school within its premises.
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.