The paper is devoted to several architectural principles and building types typical for the late Roman architecture, which could reflect the authoritative concepts and influenced the early Christian architecture. In the architectural theory mainly based on the conceptions of R. Krautheimer and J. Ward-Perkins, the idea that the early Christian architecture has but a few links with late Roman pagan buildings is still vivid. However, A. Grabar proved that many motifs of late Roman art which came from the culture of the ancient Near East had an influence on the early Christian iconography. It seems possible for architecture as well. It is necessary to pay attention to three main architectural features and their meanings.
The first one is the usage of halls with apsidal ends which were typical both for pagan and Christian religious architecture in the 3rd–4th centuries, as well as for luxurious palaces and villas of late Roman nobles. This tendency could develop due to the new religious and political concepts of tetrarchy. They were probably based on concepts of ancient Near Eastern kingship and the new hierarchical organization of ruling class mainly of former military officers.
The second architectural type chosen for study is the tetrastyle (four triumphal columns placed at the crossroads in a city or fortress). It had a wide usage during the first tetrarchy and probably was connected with the idea of concordia — harmony between four rulers. There was a later example of such monument built in the time of Justinian with figures of the evangelists on the columns. H. Bogdanovich supposed that this architectural form could be the probable prototype for the Christian ciborium. In the third place the origin of the latter architectural element is of peculiar interest. Due to the wide numismatic evidence it is known that the baldachin with four supports and flat roof, cylindrical vault or cupola was one of the attributes of God’s or divine ruler’s representation. This motif could come to the Roman culture from the architecture of ancient Egypt and the ancient Near East.
The examination of these three motifs which influenced some features of the early Christian architecture together with the authoritative and religious concepts which they expressed could be very fruitful and important for architectural theory.