Le Perthus became French territory after the Treaty of the Pyrenees (1659). The Spanish captured Bellegarde in 1674 and began work on new fortifications in 1675. These were not very far advanced when the place was recaptured by the French. In 1678 Vauban designed for Bellegarde a strong pentagonal fort with a detached hornwork extending southwards towards the frontier.
The defences consist of a five bastioned trace, with an upper tier and a lower tier. In front of the more vulnerable sections of wall, there is a ditch. There are three demi-lunes, again only on the more approachable sides of the fortress - on the east there is a sheer precipice.
During the War of the Pyrenees, the fortress was besieged in May - June 1793 by the Spanish and then by the French (in 1794).
During World War II, the fort was used as a holding prison by the Gestapo for escaped prisoners of war and enemy agents.
The fort is open to the public between June and September only and includes exhibits on the history of the fort, its archaeology and the surrounding area.
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.