The Episcopal Complex of the Euphrasian Basilica in Poreč

The Episcopal complex of the cathedral of Poreč—known as the Euphrasian Basilica, as it is named after Bishop Euphrasius, who built the cathedral towards the middle of the sixth century and decorated it with its famous mosaics—is a magnificent example of Paleo-Christian art, and has been classified as a UNESCO world heritage site since 1997, due to its exceptional state of preservation. This monument, a fine example of the architecture during the reign of the Byzantine Emperor Justinian I (reigned 527–565), is located in the historic centre of the town of Poreč, in Istria (Croatia).

Several buildings had existed on this site before the work initiated by Bishop Euphrasius began. Archaeological remains and epigraphic documents attest to the existence of an earlier sanctuary on this site, the domus ecclesiae of Saint Maurus of Parentium, the first bishop of Poreč who died a martyr in the third century. The first public church, built in the fourth century, comprised three square rooms of unequal dimensions; the northern room probably served as a baptistery. The remains of this building and fragments of the floor mosaic that ornamented it are kept in the northern part of the Euphrasian Basilica. 

Towards the middle of the fifth century, an ensemble of Christian buildings was built on the site of the former church. This complex, known as pre-Euphrasian, comprised two parallel three-aisled basilicas (basilicae geminae) separated by a narrow aisle and a cistern. The plan of the southern basilica, apart from the eastern part that terminates with a straight wall, is identical to that of the Euphrasian Basilica that succeeded it. The sanctuary housed a synthronon, a semi-circular seat for the bishop and priests. The floor mosaics from this basilica are kept in the crypt beneath the current basilica. There are archaeological remains of the northern, smaller basilica. Its synthronon and the remains of the floor mosaic are kept in the crypt beneath the sacristy. The pre-Euphrasian complex also comprised an octagonal baptistery with hexagonal baptismal fonts built into the floor.

Towards the middle of the sixth century, following Justinian’s reconquest of Italy, Euphrasius became bishop of Poreč. Thanks to the extensive work he carried out, the Episcopal complex was entirely renovated and new buildings were added. A memorial chapel, a new atrium, and an episcopal palace were built; the baptistery and the small basilica were kept in the complex. The Episcopal palace built to the north of the quadriporticus is a two-storey building, with semi-circular apses, and a large courtroom on the first floor (audientie episcopalism) ornamented by a central tri-lobed arch, whose marble capitals, decorated imposts, and polychrome stucco are well preserved.

The large basilica dedicated to the Virgin Mary was entirely renovated. It was enriched with a new colonnade, decorative work, and a new sanctuary. The columns with sumptuous capitals and the furniture in Proconesian marble, characteristic of Byzantine sculpture in the middle of the sixth century, were probably produced in the imperial workshops and then transported to Poreč once completed. The new sanctuary with three apses was entirely covered with mosaics. The representation of Christ being held by the Virgin on the throne surrounded by angels and martyred saints constitutes the principal part of the composition, which has a rich iconographic repertoire.