This article is taken from the March 2022 issue of The Critic. To get the full magazine why not subscribe? Right now we’re offering five issue for just £10.

If you’ve ever wondered how letters were delivered in the ancient world, you could do worse than to read Procopius’s Secret History. Every bit as scandal-filled as Donna Tartt’s classic campus novel of the same name, it describes life in the court of Justinian, Byzantine emperor from AD 527 to 565, but digresses brilliantly on the intricacies of the Roman postal service.

It is hard to think of another historian who applies such a scientific approach to ancient history

The cursus publicus was hailed for its efficiency, at least until Justinian got his hands on it. Procopius claimed that a message entrusted to the system could cover ten times the distance of an individual in a single day. It worked by running couriers between a series of stations arranged along established routes. Each was equipped with 40 horses and an equivalent number of grooms and, in some cases, overnight accommodation.

There was not, as you might have imagined, a changeover of courier, but rather of horses. The same tireless postie covered between five and eight stations by horse-drawn carriage per day or, by the calculation cited in this book, up to 120 kilometres if the missive was particularly pressing.

Stephenson, a prolific scholar of Byzantium, has a wonderfully sharp eye for data and detail. His book examines the journey by which the Roman Empire progressed from being ruled from several different cities in the fifth century, among them Alexandria, Antioch, Constantinople and Rome itself, to just Constantinople, home to Procopius, and the “New Rome” of the book’s title.

I sat down expecting a narrative history of the fall of Rome, but was pleasantly surprised to find a portrait of the changing empire populated by statistics and technical hypotheses of a kind one would usually encounter in a copy of the Economist. The first ten pages alone contain references to cosmogenic radionuclides, the Maunder Minimum and the Early Anthropocene. I confess I needed a dictionary.

It is hard to think of another historian who applies such a scientific approach to ancient history, except perhaps the Stanford professor Josiah Ober, who has applied political theory and modern economic modelling to information garnered from classical sources to equally eye-opening effect. The terminology is not off-putting because Stephenson proves able to weave it succinctly and fluidly into his account of how the Late Empire functioned.

Constantinople, formerly Byzantium, was the principal base of the emperors from Theodosius I (“The Great”) in the final quarter of the fourth century onwards. The city was beautified with a wide variety of art and architecture, including the famous Egyptian obelisk, the arrival of which in the late fourth century is seemingly as mysterious as the appearance of the monolith in 2001: A Space Odyssey.

The new Hagia Sophia rose under Justinian in less than six years thanks to the work of 10,000 builders. A rival to not only the Pantheon in Rome, but also the Church of St Polyeuctus in Constantinople, the building apparently boasts such sophisticated acoustics that — according to another great detail in this book — a reverberation beneath its dome can last up to 11 seconds compared to just two or three in modern concert halls.

For all its beauty, life in Constantinople was often unsanitary, and difficult. “The porticoed streets and baths were thronged with citizens,” Stephenson writes, “most of them with chronic ailments and bad breath.” Up to 40 per cent of people born during the Late Roman Empire died before the age of 18.

Many of them would unknowingly have been suffering the ill effects of exposure to pollution. The main source of this in Roman times, says Stephenson, was smelting, especially of silver coins issued since the first century, which released lead into the atmosphere. While it was usually slaves who were on the front line of this process, practically everyone was at risk owing not to water pipes, but to their use of saucepans, typically made from lead and tin.

Natural disasters (or were they?) also played a part

Attempts to answer the time-old question of why Rome fell have been characterised in recent years by a new awareness of the role that factors including pollution and climate change played. Anyone who has shrugged at the suggestion that the weather had anything to do with the demise of such a mighty empire will, I think, come away from this book persuaded that climate change and natural disasters provide an important part of the answer. Far from being moralistic and attempting to apply the examples of the past as a warning, Stephenson lays down the evidence unemotionally, and lets it speak for itself.

The causes of change were not purely driven by human behaviour, though smelting and, even more so, heavy warfare in the era of invading Huns and Vandals, had a significant environmental impact. Pollen records reveal a dramatic decline in the growing of cereals in Greece by about 600AD and, from the seventh century, pollination was happening predominantly through nature rather than agriculture.

The root cause of this was the destruction of arable land following invasions and the decline in human settlements. Add to this diminishing sunlight — measurements of “deposited radionuclides” indicate a significant reduction of light between the midfourth and late seventh centuries — and we are looking at a radically different landscape in this period from that of the High Empire.

Natural disasters (or were they?) also played a part. The later fifth and early sixth centuries witnessed a number of major volcanic eruptions. Vesuvius, which famously buried Pompeii when it awoke from seven centuries of dormancy in 79AD, erupted in 472 and 512, bookending, as Stephenson notes, the overthrow of the last Roman emperor, Romulus Augustulus.

Another as-yet unidentified volcano erupted in the northern hemisphere 24 years later. A contemporary account records the eclipse of sunlight. The event is confirmed by evidence from tree rings and ice cores. In the same period, Constantinople suffered the effects of an earthquake, famine and plague, the last of which was believed to have originated in Africa about 540. Such was the plague’s virulence that, by spring 542, it was said to have claimed 10,000 victims a day. Within two years it had reached our shores.

A sobering but fascinating history

The effects of Yersinia pestis, the bacterium responsible, have been identified in human remains interred at Edix Hill in Cambridgeshire and elsewhere. Although the disease is long thought to have been carried by fleas on rats, the lack of rat bones prompts Stephenson to doubt that rats were the principal vectors.

It was only natural for people living through these dire days to blame the gods or a decline of religion. Some even drew a connection between the darkness following the volcanic eruptions and the outbreak of plague and war as the future of the empire hung in the balance. Stephenson is more cautious: “Whether there is any direct or causal link between the global climate event and the arrival of plague in the Mediterranean basin has not yet been determined.” Nevertheless, the accumulation of material he cites, carefully tied to the chronology of events, makes it difficult to deny a connection.

Parts of the book are uncomfortable reading in light of current world events. The plague that swept the empire kept coming back, recurring throughout the sixth century and even into the mid-eighth, at the same time as the light was faltering and unknown volcanoes were continuing to throw up their pestilence to further darkness. Papyri cited by Stephenson indicate that taxes rose to three times higher than their rate before the plague pandemic, reflecting not only the disruption and death toll brought about by the disease, but the effects of crop failures and climate events, too.

All this makes for a sobering but fascinating history. Not for a long time has a book surprised me as much as this one did. What it lacks in narrative drive it more than makes up for in scope and close scrutiny of scientific evidence. I have been quoting passages and surprising facts to everyone around me ever since putting it down.