Representational art is a particularly important source. As the emperors themselves became more remote from their subjects, the manner in which their images were publicly presented became more contrived, and carried elaborate encoded meanings. This is particularly evident in fourth-century representations of emperors and members of their families, which were subtly designed, according to well-understood conventions, to convey essential propaganda messages about the regime. They express ideal relationships between the rulers and their subjects. Free standing sculpture such as the porphyry groups depicting the tetrarchs, figured friezes, like those on the obelisk base of Theodosius I in Constantinople, and decorated silver plate, like the missorium of Theodosius from Madrid, are a visual counterpart to the imperial panegyrics. They provide a key to understanding how rulers conceptualized their office.81 Portrait-sculpture and coinage were also vital media for the presentation of a ruler. During the period of Diocletian and Constantine portraits were used more than at any time since the age of Augustus to project and differentiate the character and regime styles of the emperors, and accentuated the competition between them (Plate 2.2).82 There was also still room in the fourth and fifth centuries for statues of leading public figures, displayed along the streets and in the main squares of provincial capitals and other large cities.83 Notable groups have been found at Ephesus and Aphrodisias, and exemplify the tradition of display that remained central to civic life in the eastern empire. The choice of subject reflected cultural developments in late antiquity. A large house that seems to have housed a pagan philosophical school at Aphrodisias was decorated with a series of tondo portraits of famous intellectual figures from the Greek tradition. The hippodrome at Constantinople was adorned with major monuments for successful charioteers (Plate 4.1).84 Imperial images on coins at this period were also designed on the same principles. However, a major change is observable after the end of the fourth century. It becomes impossible to distinguish one imperial bust from another on most fifth- and sixth-century coin issues. As the emperors themselves retreated into the seclusion of the palace, their authority derived not from individual charisma and presence, but from the immanent sacral and institutional power of their office. The coinage matched this development. In the later Byzantine period, the imperial image vanished altogether and was replaced exclusively by Christian symbolism.
Plate 2.2 The head and other fragments of a colossal marble statue of the emperor Constantine, now on the Capitol at Rome. The emperor's upward gaze is explained by Eusebius, Life of Constantine 4.15: “In the imperial quarters of various cities, in the images erected above the entrances, he was portrayed standing up, looking up to heaven, his hands extended in a gesture of prayer” (S. Mitchell)
However, the largest advances in understanding late antiquity from a material perspective have not come from representational art, but from the archaeological study of settlements and settlement patterns. In particular enormous attention has been given to investigating the remains of cities throughout the empire. Civic life from the fourth to the sixth century is now no longer viewed through the lens of Roman legislation, as it was when A. H. M. Jones completed his massive survey of the later Roman Empire,85but as the much more complex organism revealed by archaeology. Especially in the East it is now clear that the booming urban development of the early imperial period did not go into recession, but continued through the fourth and fifth centuries.86 More settlements were described as cities in the Synekdemos of Hierokles, compiled in 527, than at any earlier period, and the evidence on the ground suggests that many urban settlements were larger than they had ever been. Of course archaeology demonstrates not only continuity and growth, but also wholesale urban transformation, which accompanied Christianization and other deep-rooted social changes. Meanwhile in the western part of the empire, archaeological survey of rural settlements has been equally important in tracing the end of Roman villas and the steady encroachment of a smaller scale, more localized village society across western Europe at the expense of the earlier imperial structures and networks. The degradation of material culture, exemplified through the archaeology, now provides the most vivid illustration of the decline of the Roman Empire, especially in the West.87
In both halves of the empire archaeologists have paid particular attention to the evidence for trade, commerce, and exchange, especially by sea. Amphorae, which were used for transporting oil, wine, and other foodstuffs, are the trace element for the movement of goods in patterns of long distance maritime trade. They have become the starting point for almost all serious work on the late Roman economy.