The Basilica of the Holy Mother of God Eleusa is a former monastery church situated in the UNESCO World Heritage town of Nesebar in Bulgaria.
The church, on the northern side of the peninsula, was built in the 6th century. It is recorded until the 14th century, and formed part of a monastery complex. It is presumed to have been destroyed by an earthquake.
The northern part and the central nave had sunk into the sea, but in 1920 excavations and research began here, and the church is now well-preserved and partly restored.
It has three naves, three apses and a narthex, with two smaller apses on the north and south sides. It is 28 m long and 18 m wide.
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.