There is no real break between Classical art and that of the Middle Ages; the early Christian was the last phase of Roman art, and the Church handed on with the Christian religion a mass of Judaic and Latin culture which the barbarian races, having none of their own, accepted, but through their different nature and requirements, modified and debased. Thence we see the continuity, and also the two main causes of the deterioration of Classical art: first, by the rise of Christianity, which was in its early days antagonistic to the plastic arts, owing to a haunting horror of images, inherited from Judaism, and a fear of falling back under the pagan spell of sensuous beauty: and though later and for a long period the Church became by far the most munificent and inspiring patron, the final tendency in the Eastern Empire was to stifle the true spirit of art by subjecting it to as dogmatic a rigour in design as in doctrine. Secondly the near presence of the powerful and rapidly assimilating barbarian, who imitating all things, often ignorant of their meaning, and incapable of good workmanship, reduced art in the Western Empire to the lowest ebb. In Constantinople there lingered a fading shadow of the old Greek spirit, which, at least, inspired the craftsman to finished workmanship and a love of elegant form. In spite of the paralysis caused by the enforcement of a fixed canon of iconography there were long periods of high artistic excellence (Figs. 17 and 18). We have an exaggerated idea of the rigidity of Byzantine art owing to the numerous repetitions by inferior craftsmen which are found in our museums, and by confusing the Golden Age, with the period of real deadness which commenced in the twelfth century, and has lasted to this very day in the art of the Greek Church. Byzantine art became the technical school of the younger nations, teaching them craftsmanship and design, thus enabling them to express their more impulsive religious emotions and leading them on till they found the full expression of their genius in the aspiring beauty of Gothic art. The best period for commencing the study of mediæval ivory-carving is with the fourth century, A.D., and the great series of Consular Diptychs which form the backbone of the early history of the craft and created a type which lasted through the whole mediæval era. Theodosius the Great (✝395), divided the Roman Empire between his two sons. Arcadius ruled the Eastern Empire, his capital continuing at Constantinople. Honorius, then only eleven years old, nominally governed the Western. He did not make the Eternal City his seat of government, in fact the Imperial Court had rarely returned there since it was deserted by Diocletian. Milan was considered too exposed to the attacks of the barbarians, so the city of Ravenna, almost impregnable owing to the surrounding marshes, was chosen, and remained the capital of the varying rulers of Italy until the eighth century.