The Golden Octagon

The Golden Octagon (domus aurea) or the Great Church as it was sometimes known was an Antioch landmark that did not stand the test of time even by the relatively short-time spans of the rest of Antioch's monuments. Once again, it succumbed to an earthquake but was in existence for scarcely 300 years. However its memory lives on.

The four most accessible sources on this subject are an article in German by F.W. Diechmann, an article in French by Catherin Saliou questioning the rationale for relying upon the Megalopyschia Hunt mosaic as an accurate source, an esoteric yet informative essay by David Woods on the foundation-stone inscription and a non-literary source in the form of the Megalopsychia Hunt Mosaic itself. This latter artwork was unearthed in Daphne (Yakto), the resort suburb of Ancient Antioch, by the Princeton-led expedition in the 1930s.

The Octagon was begun in 325 AD in the reign of Constantine I (306-337AD). The edifice was finally dedicated on the 6th of January 341 AD. It was severely damaged in the earthquake of the 29th of May, 526 AD and collapsed several days later. It was then rebuilt (while the rest of the Island seemed abandoned) and then was toppled again in the earthquake of the 588 AD and never rebuilt.

Saliou quotes Malalas as indicating that the Octagon was built over the demolished "thermes de Philippe".

It is most useful to begin by discussion of this work. A large mosaic of the aforementioned hunt is surrounded by a border and instead of the typical geometric border instead there is a form of tourist guide to Ancient Antioch. In what is believed to be a consecutive order of images the viewer is taken for a stroll through Daphne and roundabout Antioch. Included in this are images of important structures in little vignettes. The most relevant are those dealing with the sights of the Island (shown below). Amongst these are the Golden Octagon and what is presumed to be the Imperial Palace. There is also a gate structure thought to represent the Porta Tauriana (mentioned elsewhere in our writings in relation to the city gates). As Saliou rightly points out this could be a reference to a totally different location (possibly the district built up by Varius) and she also notes that the mosaic may not be a source that is consistent in its ordering of the monuments it shows.


The mosaic is groundbreaking as it gives us what is believed to be the only extant image of the Golden Octagon. This was a form of royal chapel rather than being the city's cathedral. The subject of the Deichmann article is a debate above the relative merits of various theories as to the status of the structure. Was it a chapel for the palace and the emperor? Was it a Martyrion for Saint Babylas or other saints? Was it a Heroon for the cult of the Emperor?

However, is the structure really the Octagon at all? The eight-sided shape was all the rage in the period when it was built and many examples exist of buildings in the octagonal form. Was it really just the martyrium of Saint Babylas (ruins of which were discovered across the bridge from the Island by the Princeton team) or some other church? Some have interpreted the figure with the upraised hand as as a bishop thus investing the nearby building with episcopal purpose. However, the upraised hand is a feature of Babylas "mythology" as well. We recently came across (serendipitously) a silver reliquary of the saint's forearm in the Philadelphia Museum of Art and it is in the same upraised arm format.

The further question provoked by considering the structure are: was it part of the palace? Most commentators suspect it was nearby but was it actually integrally part of the palace complex? The octagonal shape coincides with the shape of the mausoleum that Diocletian built as part of his palace at Split (see the plan of Split on the commentary on the Imperial Palace).

The image above shows the church of San Vitale at Ravenna which was built in the 540s AD and which some speculate could be like the Golden Octagon. It is plain brick on the outside but inside is sumptuously decorated with golden mosaics showing the Emperor of the time and various saints and other relious images.

Giovanni Rivoira in his volume Moslem Architecture states that Constantine's octagonal church at Antioch was alleged as the prototype of the design of polygonal structures with recessed rectangular or semicircular niches as its interior displayed an alternation of such recesses. In support he quotes Eusebius' Vita Constantini III: 'Within, the house of prayer was raised to an immense height, having the form of an octagon, surrounded on every side by chambers (or compartments) both on the upper and on the ground floor.' He also cites De Vogue's Syrie centrale. Architecture civile et religieuse du 1' au VII' Siècle in relating that the Octagon seemed to have had a flat roof.

Markus Bogisch in the 2004 edition of Byzantino-Nordica quotes Eusebius:

"(At Antioch) he consecrated a church really unique in size and beauty. On the outside he surrounded the entire church with enclosures of great extent, while the interior of the house of prayer he raised to an immense height. This was made in the form of an octagon ringed all round with chambers both on the upper and lower levels".

Clearly a translation of the same piece as Rivoira but Bogisch's version seems to suggest a much larger complex, maybe a portico surrounding the structure.

Bogisch goes on to comment: " Together with the second account of Eusebius, where the spaces surrounding the centre are described more accurately as oikoi and exedrai, this gives us a basic idea of the monument: it consisted of a large octagon enclosed by a ring of chambers and exedras. The exedras might have been placed in accordance with the main axes of the octagon, which would have effectively turned the building into a tetraconch, or in line with the diagonals like it is in the Church of Sts Sergius and Bacchus in Constantinople".

Saliou's piece on the subject of interpretation of the Porta Tauriana reference is an eye-opener. She makes a good case that it is not a "given" that the Octagon was near the bridge/gate of that name, or even that the bridge/gate was next to the Imperial palace. The Island was a big place. Only excavation will clear up the mystery.