The mosaic decoration of the Rotunda is a masterpiece of Late Antique art. The mosaics form one of the oldest ensembles of wall mosaics preserved to a large extent and in good condition. Originally, mosaics covered the entire hemisphere of the dome, the lunettes at its base, and the barrel vaults of the rectangular niches on the ground floor. Today nearly all of the lower zone of the dome and part of the decoration on the lunettes and barrel vaults of the ground floor remain. The mosaics are unique in their conceptual design and of unparalleled artistic excellence, and their interpretation and dating continue to attract researchers.
The main iconographic program unfolded in the dome, which dominates the unified circular space of the monument as if a world of unsurpassed beauty was built to emerge in the enormous interior of the vault. The composition consists of a single scene organized in three successive concentric zones around the honored personage, who was depicted in a silver medallion at the apex of the dome. Today, one may discern in the charcoal preliminary sketch the triumphal standing figure of a man, and on the preserved mosaic part of the halo, his right arm in an attitude of omnipotence, and the end of a rod or scepter he carried in his left hand. The medallion—surrounded by stars, a wreath of glory of the earth’s everlasting bounty, and a rainbow—is borne by four archangels aloft in golden light. To the east between the angels is the phoenix, the mythical bird-symbol of renewal and eternity.
The middle zone has been completely destroyed, with only the feet of figures dancing on a lush green ground preserved in places. Between 24 and 36 males were depicted in this multi-figure scene, forming a dance of praise. We can only hypothesize about their identity or status.
In the zone nearest viewers at the base of the dome, complex architectural assemblages are depicted with combinations of arches supported by columns, gabled tetrapyla, domed ciboria, pavilions, porticoes and other buildings standing on crepidomas (platforms) and unfolding at two levels reminiscent of theater sets. The buildings are richly decorated and display obvious similarities with the architectural urban landscapes of Pompeiian painting, the false facades of Roman buildings, and the rock-cut tombs at Petra in Jordan. Through the arched openings of the buildings, men at prayer appear in groups of two or three per panel. Inscriptions state their names, attributes, and the month of their feast day. Three generations are presented: young military men for the most part, followed by middle-aged physicians and presbyters, and then by elderly bishops. They stand solemnly and piety is manifest in their facial expressions.
The prevailing interpretation is that the men at prayer were martyrs of the Christian Church, the luxurious buildings were a representation of the Heavenly Jerusalem and in the apex of the dome, Christ was shown either ascending into the heavens or arriving on Judgement Day (the Second Coming). Various other interpretations have been proposed by those who have focused on the intensely secular character of the lower zone of decoration, which departs from the soteriological-Eucharistic content of the iconographic programs in Christian churches. Within this context, the honored personage has been identified as Constantine I, the first Christian, a triumphant emperor and in all likelihood the founder of the Rotunda. In this case, the architectural setting which included the Christian bishops and presbyters in tandem with the pagan court officials.
The mosaics of the lunettes at the base of the dome complement the luxurious character of the decoration. Elaborate compositions of geometric and floral motifs framed by garlands create a sense of optimism and infinite creativity. Some motifs are repeated in the mosaics which cover the barrel vaults of the niches on the ground level. Here, the depiction of a large cross with bars of unequal length dominating the barrel vault of the south niche is of special interest. Stylistic and construction features date this mosaic to a different period of decoration than the rest of the monument’s decoration. The cross makes the validation of the monument’s Christian identity undeniable, giving emphasis to the south niche, that which was facing the palace, from which the Rotunda was entered both when it was founded (4th c.) as well as when it was later converted to a Christian church. The dates proposed for the mosaic decoration range from the early decades of the 4th century to the mid-6th century.
website text by Pelli Mastora, archaeologist
Source of photographs : Κουρτίδου-Νικολαΐδου et al. 2012: Ε. Κουρκουτίδου-Νικολαΐδου, Χ. Μαυροπούλου-Τσιούμη and Χ. Μπακιρτζής, Τα ψηφιδωτά της Θεσσαλονίκης, 4ος-14ος αιώνας, Athens, 2012
