The magnificent Rotunda temple in Thessaloniki is the most significant monument of the early Christian period. In this detailed monograph, Hjalmar Torp presents the conclusions of the archaeological and iconographic research he has conducted on the Rotunda throughout his life.

The archaeological data, architectural phases, and chronological problems of the monument are investigated. The detailed descriptions of the mosaics, colors, and techniques are based on an analytical, on-site examination of the decoration on scaffolding. Based on this, the iconography of the mosaics is analyzed and interpreted according to historical and theological sources.

The creation of the imperial temple and its luxurious decoration is attributed to an initiative by Emperor Theodosius the Great. This edition, with extensive documentation and rich illustration, serves as a unique testimony to the Rotunda.