The Euphrasian Basilica in Poreč is one of the best preserved monuments of early Byzantine art in the Mediterranean. It was erected in the 6th century in Poreč, during the time of Bishop Euphrasius. Though it is somewhat smaller than the remaining preserved basilicas of the same period, it is unique in that it is the only church of its type with the original structure preserved.
The main structure of the complex is the three nave basilica, with the central nave wider and taller and separated from the side naves by two series of arcades. All three naves end in semi-circular apses, while in the main apse, taller and wider than the other two, is the ciborium. In the northeastern corner of the basilica, the trefoil Memorial Chapel is connected with an elliptical vestibule, while the external vestibule is connected with the spacious quadratic atrium. On the western side of the atrium is the octagonal baptistery.
In the region between the northern side of the atrium and the seashore, a second large church was built at the same time, with its axis vertical to the axis of the main basilica, and new additions were made during the Middle Ages, when it was transformed into the Bishop’s Palace. Much later, the remaining structures of the complex came into being. In the 18th century, the entire complex suffered significant damage, many sections were destroyed and the complete restoration was conducted following World War II.
The Euphrasian Basilica is richly ornamented in the Byzantine style of mosaic (which, with the mosaic of the Church of San Vitale in Ravenna represent the most significant examples of mosaic art in Europe). The basilica is also ornamented with incrustations, stucco and plaster.