The decisive step is often attributed to Peter Brown, whose World of Late Antiquity was first published in 1972. But there were other authors too, including French and German historians, and a clearer awareness of multiple approaches – to some extent differentiated along national lines – helps to grasp the multiple aspects and trends of a civilizational complex that encompassed the Mediterranean as well as an important part of the Near East. Chronological boundaries are still disputed, but the present reviewer tends to agree with those who define late antiquity as the roughly three and a half centuries between the beginnings of imperial reform under Diocletian (284-305) and the rise of Islam in the early seventh century.

Historians have singled out several defining features of the period. The Christianization of the empire was also, less obviously but increasingly emphasized in recent scholarship, a Romanization of Christianity. Both developments took place in the context of major changes to the geopolitical balance between Rome and its neighbours, including the Eurasian nomads whose sudden appearance on the scene upset all established patterns. The reconsolidation of the empire after the third-century crisis was at first accompanied by a division of the imperial centre, but this soon gave way to reimposed sole rulership, now Christian; a more lasting division between eastern and western holders of the imperial office prevailed after 395, and the sequel led to a definitive – certainly unintended – divergence of imperial trajectories on the two sides of the internal border. This alternation of unity and division was closely linked to the destinies of two eminent urban centres, Rome and Constantinople. No other civilization or historical period seems to have known a similar constellation. It has long attracted the attention of scholars, but the book to be reviewed here takes the discussion to a new level.

An overall assessment of the relationship between the “two Romes” is to be found in the first section (pp. 3-80), which contains an introduction by Lucy Grig and Gavin Kelly, as well as chapters by Lucy Grig and Bryan Ward-Perkins. To sum up, the changing configuration of the two Romes is to be understood as a long-term process, beginning with the refoundation of Constantinople (formerly Byzantium) in 330 and ending with Justinian’s reconquest of Rome in 536. The latter event confirmed the political ranking of Constntinople as an imperial capital and Rome as a subordinate outpost (not that later relations and interactions between the two cities were unimportant; but that story does not belong to late antiquity). But Constantinople was not just a Christian capital built to replace a pagan one and then gradually marginalizing it. In fact, the very notion of capital must be used with care. Emperors had mostly resided away from Rome for some time before 330, and although Constantine clearly saw his new Rome as a residence, his successors at first preferred Antioch. There was, of course, a kind of centrality that was not strictly dependent on the ruler’s presence (it was never quite true that Rome was where the emperor was); the fact that a senate was set up at Constantinople, and nowhere else outside Rome, shows that the new centre shared an exclusive status. And being part of Constantine’s settlement, the new Rome was necessarily more Christian than the old one. But this was not the whole story. The very decline of imperial presence in the West enabled the Roman ecclesiastical authority, whose special status was originally derived from the imperial connection, to stake its own claim to primacy in the spiritual field; these efforts did not shape the history of late antiquity, but were decisive for the subsequent trajectory of Western Christian civilization.

The epilogue to the book, written by Anthony Kaldellis, develops an argument (adumbrated in other writings by the same author) that diverges from the editors’ views in interesting ways. I do not think that the two perspectives are incompatible, but they certainly call for further discussion. Briefly, Kaldellis’s thesis is that the eastward shift of the imperial centre was both a symptom and a reinforcer of more fundamental processes. A Roman identity was taking shape in the eastern part of the empire, and it became the foundation for a national identity of the people erroneously known to Western scholars as the Byzantines. As Kaldellis sees it, we have no valid reasons to question the self-identification of the later empire and its inhabitants as Romans, and the objection that Greek became the dominant language reflects an overly modernistic view of the relationship between language and nationhood. The much-discussed Greek cultural revival of the second century was – on this view – only a prelude to the “death-throes of Greek identity” (p. 401). This is an argument with very far-reaching implications. Contrary to modernist claims, historians have shown that European processes of nation formation go back to the Middle Ages, including the early phase of that period; to add the Byzantines to the list of such cases would be a major innovation.

Here I have mainly emphasized the first and last parts of the book, because they contain the matters of most general interest. But a brief description of the other chapters should be added. They contain case studies of sources, developments, policies and ideas concerning the two cities, sometimes with a comparative focus. Some paticularly interesting pieces may be singled out. John Matthews (pp. 81-115) discusses the fascinating story of the sixteenth-century French adventurer Pierre Gilles, sometimes described as the founder of the scholarly study of Constantinople, and his use of a crucial late antique source. Mark Humphries (pp. 161-182) analyzes the long reign of Valentinian III (425-455) and his abortive attempt – the last one – to re-establish Rome as an imperial centre. Neil McLynn (pp. 345-363) and Philippe Blaudeau (pp. 364-384) deal with “geo-ecclesiological” relations between Rome and Constantinople. And to end on that note, it may be suggested that the book would have benefited from closer examination of one distinctive feature of the eastern empire: the metropolitan constellation of Constantinople, Antioch and Alexandria, to which we can add Jerusalem as a religious centre, albeit not a city of the same calibre as the others.