With exceptions, all the monuments of Ravenna belong to the days of transition from Roman to Medieval times, and the greater part of them come within the fifth and sixth centuries. It was then that Ravenna became, for a season, the head of Italy and of the Western world.
The sea had made Ravenna a great haven : the falling back of the sea made her the ruling city of the earth. Augustus had called into being the port of Caesarea as the Peiraieus of the Old Thessalian or Umbrian Ravenna. Haven and city grew and became one; but the faith-less element again fell back; the haven of Augustus became dry land covered by orchards, and Classis arose as the third station, leaving Ravenna itself an inland city.
Again has the sea fallen back; Caesarea has utterly perished; Classis survives only in one venerable church; the famous pine forest has grown up between the third haven and the now distant Hadriatic. Out of all this grew the momentary greatness of Ravenna. The city, girded with the three fold zone of marshes, causeways, and strong walls, became the impregnable shelter of the later Emperors; and the earliest Teutonic kings naturally fixt their royal seat in the city of their Imperial predecessors. When this immediate need had passed away, the city naturally fell into insignificance, and it plays hardly any part in the history of Medieval Italy. Hence it is that the city is crowded with the monuments of an age which has left hardly any monuments elsewhere.
In Britain, indeed, if Dr. Merivale be right in the date which he gives to the great Northern wall, we have a wonderful relic of those times; but it is the work, not of the architect, but of the military engineers. In other parts of Europe also works of this date are found here and there; but nowhere save at Ravenna is there a whole city, so to speak, made up of them. Nowhere but at Ravenna can we find, thickly scattered around us, the churches, the tombs, perhaps the palaces, of the last Roman and the first Teutonic rulers of Italy. In the Old and in the New Rome, and in Milan also, works of the same date exist; but either they do not form the chief objects of the city, or they have lost their character and position through later changes. If Ravenna boasts of the tombs of Honorius and Theodoric, Milan boasts also, truly or falsely, of the tombs of Stilicho and Athaulf. But at Milan we have to seek for the so-called tomb of Athaulf in a side-chapel of a church which has lost all ancient character, and the so-called tomb of Stilicho, tho placed in the most venerable church of the city, stands in a strange position as the support of a pulpit.
At Ravenna, on the other hand, the mighty mausoleum of Theodoric, and the chapel which contains the tombs of Galla Placidia, her brother, and her second husband, are among the best known and best preserved monuments of the city. Ravenna, in the days of its Exarchs, could never have dared to set up its own St. Vital as a rival to Imperial St. Sophia. But at St. Sophia, changed into the temple of an-other faith, the most characteristic ornaments have been hidden or torn away, while at St. Vital Hebrew patriarchs and Christian saints, and the Imperial forms of Justinian and his strangely-chosen Empress, still look down, as they did thirteen hundred years back, upon the altars of Christian worship. Ravenna, in short, seems, as it were, to have been preserved all but untouched to keep up the memory of the days which were alike Roman, Christian, and Imperial.