Thessaloniki, The Rotunda

Also known as Hagios Giorgios; Church of St George
Era 4AD - 8AD
Location Agios Georgios 570 21, Greece

The Rotunda is a simple but huge architectural structure, a massive cylinder - the walls are 6.3 metres thick and the interior diameter 24.15 metres - , pierced by eight bays and with a dome on top, with an interior height of 29.8 metres. Below the dome but above the eight bays are eight huge windows, with a further nine semi-circular lunettes at the base of the dome, making the building surprisingly light and airy. The edifice was originally built as part of the palace complex of Galerius (emperor 305-311), though its function there is unclear. At some point, presumably in the fourth (or possibly fifth) century, the Rotunda was converted into a church and the walls were covered, from floor to dome level with marble sheets, reflecting light. Mosaics survive in the drum, the dome and the vaults of the recesses. There may also have been mosaics on the exterior.

There would have been some 1414 metres2 of mosaic if so much had not been lost. The iconography of the programme is both straightforward and complicated and unclear and contentious in its meaning. There were three levels. At the lowest level in the drum, eight equal-sized panels, separated by vertical bands with plant motifs of gold, black and silver, are occupied by sixteen (originally twenty: four are now lost) praying male figures standing in pairs against a fantastic – in every sense of that word – background of gold architectural features, gemmed arcades, peacock-feathered conches and elaborate ciboria, altars and thrones. The men themselves are gorgeously clad in elaborate robes, cunningly made to suggest shot-silk and to hint at the physical bodies swathed in these garments; their faces are subtly individualised. Although the figures have inscriptions with their names, months of the year and, in some cases, a mention of a civic status and a profession (for example, the third panel to the south-west notes Damian, ‘physician month of September’, the seventh panel to the north east, Therinos, ‘soldier month of July’) it is unclear exactly who they are, why they were paired as they are and associated with specific months, how the ordering should be read and why this group of men was selected. The men might be saints or donors. They might have been shown because their relics might have been in the crypt below the church. They might have been picked because all are ‘eastern’ saints with no apparent link to Rome or Italy, and they are perhaps arrayed as an imperial bodyguard protecting the east. They could all have had a special significance for Thessaloniki. We simply do not know.

Above the men, at the next level, only feet, garment edges and short grass survive, perhaps belonging to figures representing the Apostles. In the dome itself, although again only fragments remain, it seems likely that a standing Christ was at the centre, supported by flying angels and a wonderful rainbow border, a wreath of fruit, and stars. Whether he was Ascending or descending at the Second Coming is unclear. How the whole schema should be interpreted is as uncertain as our understanding of the saints. Is this a representation of the New Jerusalem? An apocalyptic image? Heaven on earth? Do the scenes relate to the religious ceremonies celebrated in the church below? Did it have a specific meaning for the citizens of Thessaloniki? Was there an imperial message, with Christ shown as a sort of emperor flanked by his bodyguards? Parts of the composition are similar to imagery found elsewhere in Late Antique art. But at the same time, the Rotunda is totally unlike anything else surviving in mosaic.

Make sure you look at the vaults of the recesses. Here, elaborate glass mosaics in gold and silver, with geometrical motifs enclosing birds and fruit, create an intricate and rich carpet on the ceiling. Throughout the whole ensemble, details such as the modelling of clothing to create a sense of transparency and the swan friezes set into the pediments of the imaginary architecture suggest the work of very skilled artists with a close control of the medium.

It is generally taken as a given that the mosaics were installed at the same time as the conversion of the building to a church (since the builder of the Rotunda, Galerius, was renowned as a persecutor of Christians). But we do not know when the building was adapted as a church. So the mosaics have been dated at almost any point from the fourth century to as late as the seventh or eighth centuries. A range of possible imperial patrons have been mooted, from Constantine (the proposal being it was meant as his mausoleum) to Theodosios I (who used Thessaloniki as his capital city) to Galla Placidia (who spent some time in the city). Where the artists came from is a puzzle, because no surviving mosaics look anything like this.


Christianity had been brought to Thessaloniki by St Paul and in the fourth century, the city was an important bishopric under the jurisdiction of Rome. Strategically, the city sat across the major land and sea transport arteries between Rome and Constantinople. Thessaloniki was one of those cities that served as an imperial capital in the late third and early fourth centuries. It served as a base for Galerius (293-311), Diocletian’s Caesar and later his successor as senior emperor in the Tetrarchy; Constantine also employed it very briefly as his headquarters. Theodosios I used it as his capital in the late 380s; the most notable event came in 390, when the population of the city rioted against the barbarian Goths installed as a garrison there, Theodosios punished them so severely that he was forced to do penance for this by Ambrose, Bishop of Milan.

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