Augustus established a period of peace and initiated a programme of public building works, including maintaining a vast new network of public roads that created, in Whitmarsh’s words, a unique “ancient information superhighway”. This unified empire enabled a “porousness” between ancient cultures, allowing a swifter exchange of Roman, Greek and eastern literature and ideas, all of which were to contribute to both the precepts of the new Christian faith and its successful spread throughout the empire – what Whitmarsh calls “the swirl”.

The traffic was often cultural. Christian teachers and “bibliophiles” recognised early on that, in a world “enthralled with the book”, the means to gain authority and durability, to manage structure and succession, was through the written word. The narrative structure of the Gospels, Whitmarsh argues, reveals the influence of the popular new literary form of the novel, written in Greek, if often in eastern cities. Whitmarsh also cites Virgil’s Fourth Eclogue, a bucolic idyll by the premier poet of the Augustan age, which predicts the advent of a saviour figure, here possibly Augustus. Much later, Christian emperors such as Constantine the Great claimed this as evidence that Virgil had predicted the arrival of Jesus.

But if this sounds too complex or scholarly, Whitmarsh compensates with a keen eye on accessibility: Rome’s Age of Revolution is packed with fascinating facts. We learn that a single sheet of papyrus in the ancient world would have cost a third of a labourer’s daily wage. That the first beast to confront the Christian martyr Perpetua in the amphitheatre was “a ferocious cow” (anyone who has had to walk through a herd on a country hike will commiserate). My personal favourite is the second-century AD novel Leucippe and Clitophon, which offers “the longest and most enthusiastic description of the female orgasm in ancient literature”.

Ultimately, though, the volume asks the age-old question: how did Christianity outlive – and outplay – all other faiths, including contemporary eastern cults such as those of Isis, Mithras or Cybele? In the third and final part of his history, Whitmarsh outlines a series of important, interconnected “makers of Christian culture”, starting with the role of eastern “charismatics”. Like the Christian apostles, these preachers also roamed the ancient world, performing “miracles” and speaking in strange tongues, placing the apostles and the account of their deeds in Acts very firmly in the wider tradition of the eastern empire. And so, much as Augustus himself had done, Christianity survived and thrived by selectively absorbing characteristics of ancient cultures and reconstituting them in its own image.