ROMAN art was already in its decadence before the end of the Empire, and Christianity itself, together with the invasion of Italy by the Germanic races, were the chief factors in the transformation and decline.
In the beginning of the Christian era art was too much impregnated with Paganism to find favour in the eyes of those who had embraced the new faith, though it must be said that in many instances the work of the early Christian artist was strongly influenced by the form and technique of Roman art. At first, however, as the outcome of the early Christian’s antagonism against heathenism and all its works, symbolic forms, cyphers, and mono-grams were used instead of figure decoration, lest the followers of Christ should see anything that would remind them of the idolatrous similitude of the heathen gods ; but later on, when the principles, doctrines, and practice of the new religion were more firmly established, it was found by the teachers in the Church that the pictorial representation of sacred personages, and of scriptural subjects and scenes, would in some measure help, rather than retard, the spread of Christianity. Accordingly we find that single figures representing Christ, and the saints, apostles, and prophets, and also allegorical scenes were depicted, which bore a spiritual relation to doctrinal truths. Also sacred and historical events from the Old and New Testaments were represented, and treated in a symbolical manner ; for example, the Lord’s Supper was symbolized by a representation of the Miracle of the Loaves and Fishes, and of the Water turned into Wine ; the Resurrection by the Raising of Lazarus, and the Deliverance of Jonah ; Christ as the Guide of the Church, by a figure of the Good Shepherd with the Lamb upon his shoulder. The Church was typified by a ship carrying people, or souls. Christ was also represented by the Lamb that was sacrificed, and sometimes by the figure of Orpheus, with his lyre, surrounded by animals, signifying His power of drawing all men, and nature, unto Him.
We see in this early symbolism the fundamental essence and forms of all subsequent Christian art. These early attempts of Christian iconography were represented on the walls of St. Callixtus and other places in the Catacombs at Rome, some of which are still in existence.
The new religious requirements of the early Christians demanded another kind of building than that of the temples which served the older Pagan religions. At first they were obliged to hold their services in the Catacombs and underground crypts, where the altar was erected over the tomb of a saint, or martyr, but when persecution abated, and they were permitted to worship openly, and to build churches, the early Christians found in the existing basilicas, or ” kingly halls,” a type of building which might be adapted or copied in the designs of the new buildings which they deemed suitable for the devotional meetings of their in-creasing congregations. The Roman Basilica was therefore, according to many authorities, the model on which the early Christians erected their buildings, consecrated to Divine worship, and the name, ” basilica,” was henceforth adopted as that of the early Christian type of church in Italy.
The long accepted theory, namely, that the ancient Roman basilica afforded the model on which the early Christian churches were built, has been questioned by some German and other archæologists, in recent years. These authorities argue that the Christian basilica was merely an elongation, or enlargement of the proportions, of the ordinary Roman dwelling-house, where, at first, the members of the new faith assembled together for worship. If we accept this theory, we must at the same time admit that both the heathen and Christian basilicas had much in common not only in plan, but also in the ornamental details of the architecture.
Gradually, certain changes and modifications took place in the plan and design of the early Christian basilicas, due more to the ritual and requirements of the Church service than to artistic development, though in the main, the beautiful simplicity of the principal architectural features has, as a rule, been preserved in the churches of this type in Italy, so that hardly any change is noticeable in the basilicas built from the fourth to the tenth centuries. The principal modifications in the plan consisted in the addition of a transept, which was in later buildings introduced in front of the apse and extended some distance on either side of the main structure, thus giving the cross-like form in plan; and another addition was the narthex, or scourge, which was divided by a barrier from the main building, at the west end entrance, and was equal in length to the whole frontage. This was the place reserved for penitents who had regained the right of access to the sanctuary. At the east end, generally in the transept, stood the altar, frequently covered by a baldachino which rested on four pillars; in front of the altar, at the end of the nave, was a central space, enclosed by a low marble panelled screen, which was occupied by the lower clergy who formed the choir, hence the name of choir given to the place itself. A marble pulpit, called the ambone, was placed, one on either side of the choir, and from one the Gospel was read, and the Epistle from the other. These ambones were often richly decorated with mosaics. Behind the altar, in the middle of the tribuna, was the cathedra, or seat of the bishop, raised on steps, and around the semi-circle on either side were the seats reserved for the higher ecclesiastics. The rafters of the roofs were sometimes left open, without a casing, but in other instances they consisted of beams with a flat panelling, and were invariably richly decorated with ornaments in colour and gold.
The columns of the Christian basilicas, which divided the naves and aisles from each other, were, especially in the earlier buildings, as they also were in many Byzantine churches, generally of the Corinthian order, and were actually taken from the ruined temples of antiquity, and, as may be imagined, they were often of dissimilar dimensions, differing in material, colour, and workmanship ; in fact, the builders of the early Christian period simply used the heathen temples as quarries from which they obtained the greater part of the costly marbles, which were ready-made building material, and which they did not scruple to use in Christian buildings.
The crowning glory, however, of these churches was their splendid mosaic decorations, for the embellishment or ornamentation of the basilica corresponded with its architectural form, inasmuch as it did not consist of plastic sculpture, but of surface decoration in painting and mosaic. The apse, which formed the east end termination of the church, was considered the most important part of the building and always received the principal mosaics, although the side walls of the nave, and the triumphal arch, which divided the nave from the transept, were generally decorated with mosaics or paintings. The mosaics had blue or gold grounds, and the figures, especially in the apse, were large in scale, with bold and simply designed drapery, the whole effect resulting in a monumental dignity of colour and composition, thoroughly in harmony with the architectural lines of the building.