In a recent important article on the mosaics of the basilica of St. Demetrius at Thessaloniki, R. S. Cormack proposes a list of churches in the city with mosaics ‘for which a late fifth century date must be considered.’ The list comprises the Acheiropoietos basilica, the first phase of the basilica of St. Demetrius, and Hosios David. The purpose of this article is to show that the mosaics of the second phase of the Rotunda (now known as the church of St. George) should be included in Cormack's list.
The first thing to note about the Rotunda mosaics is that there has been less than unanimity concerning the date of their construction. Volbach, Lazarev and Cormack, amongst others, follow Dyggve and Torp in dating the mosaics to c. 400 or slightly earlier; Diehl and Dalton dated them to the fifth century, Weigand to the sixth and Holtzinger to the seventh or eighth century, all on largely stylistic grounds. What are obviously needed are some objective dating criteria, and these are to be found, not so much in the mosaics themselves, but rather in the building fabric and the furniture of the converted Rotunda. The conversion of the Rotunda, incidentally, consisted of the blocking of an opaion in the cupola and the addition of an ambulatory, a monumental entrance to the south, an apse to the east (Plate XXIII) and various subsidiary buildings to east and west. The mosaics were placed in the cupola and in the niches which connected the main body of the Rotunda with the ambulatory.