‘There are two kinds of barbarians: pagans and heretics.’ So declared the Christian moralist Salvian of Marseilles. When Salvian penned these words – amid the Western Roman Empire’s (ultimately terminal) fifth-century crisis – he unknowingly registered the emergence of a new, ‘medieval’ paradigm for thinking about the diversity of human societies. So Michael Maas argues, in this ambitious and elegantly written volume which considers ‘ethnographic discourses’ in the Mediterranean world from the third to the seventh centuries ce. The ‘gift’ to which the title alludes is a decidedly ambivalent one: ethnography was a gift to the imperial metropole, insofar as it helped the Romans to renegotiate their own (constantly shifting) sense of self; but it was also a problematic legacy that the Romans bequeathed to other peoples, by setting the terms for their own identity formation.

Maas’s core argument is that the Christianisation of the Roman world fundamentally transformed ethnographic thinking. In the early imperial period, citizenship above all determined the boundaries of political participation, and the worth of non-Roman groups was assessed based on their divergence from Greco-Roman norms of sedentary civilisation. By the end of the period, orthodox Christianity was the sine qua non for legitimate membership of the political community. This change had far-reaching implications for how people thought about the world. Astral and geographical determinism (discussed in chapters iv and v) were no longer conceivable: in the new worldview, the stars or climate might be said to reflect the characteristics of a people, but the power to determine the fate of nations rested with God alone. In these respects, Maas argues that Christianity contributed to the ‘disenchantment’ of the natural world. The Bible also furnished new resources for thinking about ethnicity (considered in chapters vi and vii): Christian exegetes expended considerable resources harmonising the genealogies of ethnic and linguistic diversity provided by the Table of Nations (Genesis x) and the Tower of Babel (Genesis xi.1–9).

Fundamentally, Maas believes that Christianity introduced a new, teleological way of thinking about ethnicity rooted in the expectation that all the nations of the world were destined to enter the Church. (In this connection, the ‘Great Commission’ [Matthew xxviii.16–20] and the Acts of the Apostles might have warranted further discussion.) In such circumstances, the older idea that peoples could be graded based on their degree of proximity to the civilised Greco-Roman way of life lost purchase: every nation was potentially a Christian one. These developments had a darker side, however: under Theodosius ii and Justinian, legislators made religious deviance into a public crime. Byzantine emperors accordingly placed the eradication of heresy at the centre of their field of political activity.

The contours of this argument will be familiar to readers acquainted with the work of Averil Cameron, Anthony Kaldellis and Peter Sarris. Meanwhile, scholars of the late antique West will be familiar with Robert Markus’ thesis that the sixth century witnessed the emergence of a society organised principally around a Christian/non-Christian binary. Although Maas permits himself a few baleful glances toward the ‘sectarian, medieval’ future, he mostly (and to his credit) avoids tingeing his picture of the ‘secular’ ancient world with the romantic hue that sometimes coloured Markus’ writings. The conqueror’s gift fits well into this historiographic landscape, but breaks new ground in its chronological, geographical and thematic breadth. Maas draws on sources from a remarkable variety of genres – alongside clear-cut ethnographies, we encounter geographies, chronicles, law codes, theological treatises, biblical commentaries and encyclopaedias. One of the great virtues of the book is its sensitivity to the polyphony of the sources. Adopting an intellectual-historical approach, Maas largely proceeds author-by-author. Occasionally, this method can lead to the repetition of material, but its great benefit is to prioritise context and nuance ahead of broad-brush generalisations.

Maas’s work invites further reflection on several questions. For instance, the place of gender and sexuality in Roman ethnographic thinking is not discussed in any sustained way, but warrants treatment in its own right. Likewise, the cult of saints – often thought to be the defining feature of late antique Christianity – surely created new global imaginaries rooted in the placement of saints’ tombs and the circulation of relics. Meanwhile, Maas’s ingenious claim (advanced in chapter viii) that heresiology was a Christianised variant on Roman ethnographic discourse convinces entirely, but the exceptional place of Judaism in the Christian mentality (noted parenthetically on p. 266) could have been profitably explored. Whilst Judaism was sometimes viewed as heresy, late antique authors most often characterised contemporary Jews as antiquarian ‘survivals’, stranded in the era of the Old Law (the work of Jeremy Cohen remains magisterial on this subject). This Christian tendency to portray Jews as a people out of step with history perhaps represents a sectarian counterpart to the Greco-Roman stadial theories that Maas explores at the start of the book. Finally, it is surprising that Maas devotes little space to the renegotiation of ‘barbarian’ and ‘Roman’ identities that occurred in western Europe following the Justinianic wars of the sixth century. (It could admittedly be argued that this ground has been well covered by others, such as Guy Halsall and Helmut Reimitz.) Readers are largely left to decide for themselves how well the ethnographic worldview of the post-Justinianic Byzantine world, so richly evoked by Maas, applies to the early medieval West. In this endeavour, Maas’s book could be brought fruitfully into dialogue with R. I. Moore’s still influential thesis that the first ‘persecuting society’ emerged in eleventh-century Latin Europe.

These observations do not detract from the quality of The conqueror’s gift. On the contrary, they reflect just how stimulating are the claims it presents. Maas works masterfully across scholarly siloes that have so often distorted understandings of the history of ethnicity: Greek and Latin, East and West, ‘pagan’ and Christian, ‘ancient’ and ‘medieval’. In this respect, his book deserves to be placed alongside some of the best works that have emerged from the late antique historiographic project.