The​ surviving works of St Augustine run to more than five million words. To give some sense of scale, that’s roughly 10 per cent of all the Latin literature extant from before 600 AD, comfortably more than the total published output of Charles Dickens or Anthony Trollope, and four times the magnitude of À la recherche du temps perdu. Between 395 and his death in 430, Augustine was bishop of Hippo, modern Annaba on the coast of Algeria. He lived in one of the most prosperous parts of the (by that time majority Christian) Roman Empire. Augustine’s writings on the Trinity, on the soul, on salvation, on original sin, on grace, on predestination, on happiness, love and virtue, along with his extensive biblical commentaries and six hundred surviving sermons, were the bedrock of traditional Christian thought in Europe until the 19th century. No other Latin writer in antiquity surpasses Augustine in the breadth of his interests and the originality of his thought.

One of the strengths of Catherine Conybeare’s new book is that she remains unintimidated by all this achievement. Her focus isn’t on Augustine’s contributions to Western thought, or on his shaping of Christian theology, but on teasing out his identity as ‘both an African and a Roman’. The tension between these poles was there from the very beginning. Born in 354 into a moderately privileged family in the moderately well-off town of Thagaste in the province of Africa Proconsularis (roughly modern Algeria and Tunisia), Augustine received a very Roman education based on the Latin classics, most important among them Cicero and Virgil. He was a brilliant student. At sixteen, he left Thagaste for the provincial capital, Carthage (modern Tunis), where he became a successful teacher of rhetoric. (In a brief return to his hometown he met a woman with whom he had a son, Adeodatus, ‘given by God’.) By the age of thirty – propelled by his tiger mother, Monnica – Augustine had landed one of the most prestigious posts in the Roman Empire as official orator to the imperial court, which had for nearly a hundred years been based in Milan.

This ambitious move from Africa to Italy brought its discontents. It is a recurring feature of empire that those who transfer from the territories to the centre – no matter how well educated, talented or rich – trade a superior standing in their own localities for the label ‘provincial’ in the metropolis. In Milan, Augustine, like colonial Australians or New Zealanders returning ‘home’ to London, experienced just such a social slippage. In Africa, as Conybeare observes, Augustine had felt very Roman. In Italy, he was made to feel very African. His accent was sneered at; he regretted those telltale African vowels. Monnica, who had followed Augustine to Milan, was an embarrassment as she continued to practise her Christianity in traditional African ways. The Milanese thought her custom of making offerings of food and wine at a local cemetery particularly quaint – and inappropriate. Augustine’s friends were African. That too is the common experience of many expats, who learn to stick together.

All this striking detail comes from Augustine’s Confessions, written between 397 and 401. Confessions is a testament both to Augustine’s conversion to Christianity and to the failure of his career at the imperial court. It is a remarkable and beguiling work, often described as the earliest autobiography in the Western literary tradition. Nothing else quite like it survives from the ancient world. As with any compelling first-person account, Confessions reveals as much as it conceals. Much is missing: from Augustine’s casual cruelty in failing to name the mother of his son – she is dropped from the text (perhaps as she was erased from Augustine’s life) – to a narrative of his ‘conversion’ in 386 which rewrites his shift from Manichaeism, a fringe Christian sect, to the mainstream orthodoxy of the established church, as though he had discovered Christianity afresh. Confessions ends in 388, when Augustine moved from Italy back to Africa, cutting off before the long decade which included his ordination as a priest, his consecration as bishop of Hippo and the death of his son.

Augustine’s conversion to Christianity created new complications: what did it mean to be a Roman Christian? An African Christian? Or did both these things fall short of being Christian? How all this relates to Augustine’s life in Africa and Italy is difficult to say. For the most part, Conybeare takes Augustine at his word. Yet Confessions remains Augustine’s version – and his alone. There are hardly any independent anchor points. There are no accounts from Augustine’s friends or family of their time in Milan. Perhaps this doesn’t matter. After all, identity is a discursive formation: it is constructed, contested and reshaped through texts.

On his return to Africa, and as a bishop from 395, Augustine confronted a deeply fissured church. Members of his congregation in Hippo regarded themselves as Catholic: that is, they adhered, in broad terms, to a set of beliefs and liturgical practices and to an institutional structure shared by most Christians across the Mediterranean world. But Augustine wasn’t the only bishop in town. Some African Christians refused to recognise the legitimacy of certain episcopal appointments. In their view, Catholics had been lax nearly a hundred years before in allowing priests who had buckled under the last imperial persecutions to resume their ministry once the emperor Constantine had extended state protection to Christianity. The alternative African Church, which emphasised its rigour and purity, had been led by Donatus, who died in the mid-350s. Donatists regarded themselves as (true) Christians; Augustine smeared them as ‘the sect of Donatus’.

Theological and institutional opposition to this rival church shaped much of Augustine’s preaching and writing. Donatist separatism posed a real threat to Catholic Christianity. That was Augustine’s daily experience in Hippo, where the two cathedrals were in earshot of each other. His sermons were interrupted by loud Donatist hymn singing. The dispute between the African Church and the church in Africa, as Conybeare stresses, also ‘pitted his sense of himself as African … against his loyalty to the church in which he had been ordained’. The faultlines are familiar, running between local and universal, provincial and imperial, African and Roman. ‘The church is spread throughout the whole world,’ Augustine barked to the Donatists. ‘What are you doing outside it?’

The tipping point was Catholic bishops’ success in co-opting the Roman state. Donatism was dismantled early in the fifth century, violently suppressed by imperial troops. Its most powerful legacy – and not without irony – is Augustine’s moral and theological justification for the coalition of church and state in the policing of orthodox belief. In his formulation, the intervention of the state restrained ‘men’s brazen capacity to do harm’ and ‘their urge to self-indulgence’. Only church and state working together could effectively counter the ‘sweet taste of sinning’. Just like the Hebrews in the Old Testament who were pulled back from polytheism, humanity needed law, and for the law to be enforced. No wonder that a thousand years later Augustine was the theologian favoured by the Spanish Inquisition.

The Donatists saw Augustine’s support of Roman state intervention as clear evidence of his un-Africanness. Conybeare, in his defence, surveys the evidence for Augustine’s continued commitment to being African: in his knowledge, albeit patchy, of Punic (the language of the peasantry); in the rich agricultural imagery of his sermons, sensitive to the rhythms of rural life; and in his debates with other members of the provincial elite. But his self-presentation as African must always be understood alongside his self-presentation as Roman, and his unease about being labelled as either. This anxious oscillation between local identity and imperial loyalties, which were often in conflict, is explored in Augustine’s most significant theological and philosophical work, The City of God. Composed across a long decade in the early fifth century, De civitate dei contra paganos (‘The City of God against the Pagans’) is the longest work coherently organised around a single theme to survive from antiquity. In 22 books (or, in modern terminology, chapters, most of them about twelve thousand words long), Augustine set out an impressive philosophical, theological, pastoral and exegetical programme. At its core was a robust counter to the conventional providential narrative of Roman domination. All empires justify their conquests as divinely sanctioned. The Roman Empire presented itself as carrying out a mission supported by the gods ‘to pacify and impose the rule of law’, in the words of Virgil, Rome’s greatest poet and propagandist, ‘to spare the conquered and battle down the proud’.

The City of God made an extended rebuttal of pagan religion and set out an understanding of empire grounded in brutality, oppression and an arrogant ‘lust for mastery’. This was not a manifesto for immediate social revolution. It lacked both concision and directness; rather its lengthy exposition and leisurely digressions mimicked the winding lanes, byways and cul-de-sacs of Augustine’s small-town world. In its very construction as a text, The City of God was shaped by the complexities and convolutions of Augustine’s own experience. There are romantic expressions of local identity, but they are constrained by memories of the separatist extremism of the Donatists. His criticism of empire is haunted by his own advocacy of state-sponsored coercion to deal with Donatist dissent. More fundamental still, in the sophistication and acuity of its argument (and the excellence of its Latin), The City of God’s biting critique of Rome’s imperial achievement could only have been made by an insider. It was in The City of God, as Conybeare says, ‘that Augustine’s ambiguous status … was most fully realised’.

Conybeare’s conclusion that Augustine was ‘both an African and a Roman’ would have been a profound disappointment to Augustine himself. Not because it is incorrect, but because it would have sharpened the bitter sense of his own failure to fashion for himself a fully Christian identity. Augustine had a keen perception of his shortcomings as Adeodatus’ father, as Monnica’s son, as Catholic bishop of Hippo and, above all, as a Christian. The Latin title of the Confessions – Confessiones – might best be translated as ‘self-accusations’. For some, his continual self-criticism is the admirable outworking of a genuine humility; for others, the overwrought self-doubt of a brilliant thinker slides too easily into unattractive introspection.

Perhaps Augustine’s most remarkable intellectual achievement is to have transmuted his sense of personal inadequacy into a sophisticated set of theological propositions. As Augustine saw it, Christians were a work in progress. By disobeying God, Adam and Eve had tainted all future humanity, even newborns. Their original sin had deprived mankind of the possibility of spiritual perfection in this world. This overwhelming sense of loss frames Augustine’s thinking about nature, grace, free will and salvation, as well as his insistence on a Christian’s utter dependence on God. Simply put, the duty of a Christian in this fallen world was to keep on trying. Christ was the faithful’s physician: ‘Persevere in the doctor’s care; put up with his orders as with unpleasant medicine.’ This was counsel offered in painful recognition of human failings. ‘Sins never stop seeping in, as from the waves of the sea of this world.’

Augustine’s writings are animated by a ceaseless effort to delineate Christian identity and the stark acknowledgment that it could only be realised fully in some future state. Local and imperial identities were makeshifts for a fractured humanity labouring to shape an inevitably inadequate sense of belonging. One of the most powerful aspects of Augustine’s theology is his insistence on locating himself at the centre of these conflicts. As a sympathetic exploration of his struggle, Conybeare’s Augustine the African (and Roman) is perhaps the best he might have hoped for in this imperfect world. The book he longed to write, with the working title ‘Augustine the Christian’, could be completed only in the city of God.