Gold and silver were used sparingly. Similar characteristics ap pear in the earlier Roman mosaics in the triumphal arches of St. Paul's Outside the Walls and S. Maria Maggiore (both 5th century), and remain constant in Italian Byzantine mosaic work well into the 13th century as in the apses of St. Paul's Outside the Walls (13th century) and of S. Maria in Trastevere, the upper part of the f2th century, the lower part by Pietro Cavallini (1291).
The most typical, and in some ways, the most remarkable pro duction of the Italian school of Byzantine mosaic are the half dome mosaics of the apses of the Roman basilicas. In these, not only is the stylization of the figures themselves entirely satisfac tory, but also, the naïve directness of the composition and the simple symbolism of the ornament combine to create reverent and charming beauty. In general, the upper portion of the apse dome is occupied by a half rosette which may embody a symbol of deity. Below, filling the greater part of the curve, stand the figures, varying in number with the subject, but usually the central figure is that of Christ or the Virgin Mary, or, more rarely, the patron saint. Sometimes the figures are in a symbolic land scape, with a river below, and trees on the sides ; occasionally, as a base to the composition, there is a row of lambs, representing the souls of the saved, facing a central lamb, carrying a cross and banner and symbolizing Christ. In addition to the examples already mentioned, those of SS. Cosmas and Damian (6th cen tury), S. Agnese Outside the Walls (626) and St. Marco and S.
Cecilia in Trastevere (both 9th century) are noteworthy. The apse of S. Clemente (12th century) and of S. Maria Maggiore (13th century) are exceptional; the former, in its bold covering of the dome surface with vine patterns which are, in essence, merely variations of acanthus rinceaux; the latter, because of the new spirit resulting from its design by Jacopo da Turrita and Taddeo Gaddi, whose work is more in the line of descent of later Italian painting than of Byzantine mosaic.
Meanwhile, in Constantinople, a different school of Byzantine mosaic had developed. Its earliest great monument, the decoration of S. Sophia (middle 6th century) still remains one of its most effective achievements, and although it is contemporary with the work in S. Vitale, already mentioned, it is strikingly different, both in composition and effect. The novelty appears in the use of gold mosaic as a background for all of the decorative work covering the vaults and the large scale and oriental, non-classic type of ornament ; and although the figure work is now covered with Turkish plaster and paint, the portions still exposed give an effect of unrivalled, solemn richness. In general, domes and vaults
are treated simply, with large areas of gold and borders, and occasional spots, of direct and simple ornament, often geometric, with occasional leafwork in which forms almost Persian appear. In the pendentives are great figures of the cherubim, represented merely as six great wings, magnificently filling the space in soft bluish grey. Between the windows of the large side arches, and in the apse were the figures now covered up. These have, however, been studied during an examination of the building for its sta bility under Sultan Abdul Medjid ; the mosaics were at that time carefully drawn by the Italian architects in charge, the Fossatis, so that it is possible to form a perfect conception of the original appearance. (See C. G. Fossati, Aya Sophia, 1852.) The most effective of the mosaics still exposed are those of the vaults of the narthex, the gallery immediately above it, and the cherubim in the pendentives.
The precedent of gold grounds set by S. Sophia, controlled, not only all the mosaics of Constantinople and the adjacent regions, for the next 700 years, but is also responsible for the gorgeous interiors of Monreale cathedral, 170-90, and La Mar torana and the Capella Palatina (both in Palermo, 12th cen tury). To it is also due the use of the single great head or figure of Christ in the apse, a type of religious decoration whose awe inspiring grandeur and daring beauty can best be judged at Monreale. Similarly, the ranked figures over the columns of the nave of the Capella Palatina, recall, distantly, the saints between the windows of the arches of S. Sophia. Even in Venice, the Italian school of Byzantine mosaic is entirely dominated by that of Constantinople, and the narthex and baptistry of St. Mark's (13th century), resemble the oriental patterns of Constantinople much more than the contemporary work in Rome. The vaults and domes of the main body of the church, with glorious gold backgrounds, are equally eastern, but the figures and scenes, dating from the 12th to the 16th century, have been so repaired, altered and polished, and in parts, so disfigured by the Renais sance effort to imitate paintings with an alien material, as to be individually disappointing.