“Indeed, the arcade, which had become the dominant element of Roman architecture, had nevertheless remained subject to the proportions of the Greek orders, of which the entablature served as an indispensable accompaniment; and from this medley of elements so diverse was produced the mixed style which characterises the Greco-Roman architecture. But the Christians, in separating or breaking up the arcade, in abandoning the use of the ancient orders, and in making the column the real support of the arch, laid the foundations of a new style, which led to the exclusive employment of arches and vaults in Christian edifices. The Church of St. Sophia at Constantinople, built by Justinian in the middle of the sixth century, affords the most ancient example of this system of construction by arches and vaults in a Christian church of large dimensions.” Transported to the East, the Latin style there assumed a new character, owing especially to the adoption and generalisation of the cupola, of which there were some examples in Roman architecture, but only as an accessory; whereas, in what is called Byzantine architecture, this form became dominant, and, as it were, fundamental; thus, at all periods and at each time that the architectural influence of the East made itself felt in the West, we see the cupola introduced into buildings. The Church of St. Vital at Ravenna affords, in its plan (Fig. 296) and in its general appearance, an example of this influence, which is quite Byzantine. Edifices of Latin architecture, properly so called, are rare, we might almost say that they have all disappeared (Figs. 297 and 298); but if some churches in Rome, whose foundation dates back to the fifth and sixth centuries, can be considered as specimens of this first period of Christian art, it is in the arrangement of the plan much more than in the details of execution, which for a long subsequent time since have been united with the work of later periods. In the days when Christianity was so triumphantly established as to have no fear nor scruple to utilise, in the construction of its churches, the ruins [Illustration: Fig. 296.--Church of St. Vital, at Ravenna. Byzantine style. (Sixth Century.)]