Church of St. Mary of Panagia Katholiki is a small stone church originally built sometime in the 5th century AD, on the foundations of an early Christian Basilica. Parts of the foundations are still visible today. The church is triune, which means it's dedicated to three holy people or groups of three. In this case it pays homage to the Holy Mother, St. Luke and to the three Prelates.
At some stage before the 8th century, an earthquake struck the island, causing serious damage to many buildings, including this church at Afandou, which completely collapsed. But the inhabitants were determined to replace their favorite place of worship and so in the years that followed, the little church was gradually re-erected. But it was probably not meant to be because it was again leveled during another earthquake that hit the area towards the end of the 8th century. The chapel was patiently and painstakingly reconstructed for the third time.
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.