Pompeii

In the first century AD, Pompeii was a prosperous Roman town near the Bay of Naples — a place of paved streets, painted houses, busy markets and crowded baths. Together with its smaller neighbour, Herculaneum, it was home to more than twenty thousand people, going about their ordinary lives in the warm light of an Italian summer.

Above them all loomed Mount Vesuvius, a great green shape on the horizon. Its slopes were rich and fertile, planted with vines, and the townspeople had looked up at it every day of their lives. What none of them knew — what they had no way of knowing — was that the quiet mountain watching over their prosperity was a volcano, and that it had simply been sleeping.

Then, one day in the year 79 AD — traditionally remembered as the 24th of August, though some evidence now points to later in the autumn — it woke. With a force that no one in Pompeii had words for, Vesuvius erupted.

The first phase was the most spectacular and, at first, the least deadly. Vesuvius threw an enormous column of ash and pumice some fifteen to thirty kilometres straight into the sky — so high that it spread out at the top like an immense pine tree. From across the bay, a young man named Pliny the Younger watched it from the town of Misenum and would later describe exactly that shape. This phase lasted around eighteen hours, and all the while ash and small stones rained down on Pompeii, piling deeper and deeper until the city lay buried under more than three metres of debris. Roofs groaned and collapsed under the weight.

Faced with this, the townspeople made the choices people always make in disasters. Many fled at once, pouring out towards the harbour and the roads with whatever they could carry. Others sheltered indoors, covered their heads, and waited for it to pass — reasoning, perhaps, that the falling stone could not last forever. Some were simply trapped. And one famous man chose to sail towards the danger rather than away from it: Pliny the Elder, a celebrated naturalist and the commander of the Roman fleet, crossed the bay both to rescue people and to observe the eruption with his own scientist's eyes. He went ashore — and never left.

By nightfall the city had vanished beneath the ash. But for those who had stayed and survived the first day, the worst was still to come.

On the second day, the eruption changed its character completely. Now Vesuvius sent down pyroclastic surges — fast, ground-hugging clouds of superheated gas and ash that swept down the mountainside far quicker than anyone could run. For those who had stayed behind, sheltering and hoping, there was no escaping them. The searing, airless cloud reached the city and suffocated those still within it. Pliny the Elder, who had gone ashore the day before, was among the many overcome by the fumes.

His nephew, Pliny the Younger, safe across the bay, had watched the whole catastrophe unfold. Years afterwards he set down what he had seen in two letters to the historian Tacitus — and those letters survive as the only eyewitness account of the disaster that we possess. In all, somewhere between thirteen and sixteen thousand people are thought to have died at Pompeii; the remains of more than fifteen hundred of them have since been found. The ash that killed the city also, strangely, preserved it: sealed beneath the debris, Pompeii lay buried and largely forgotten for around seventeen hundred years.

Then, in 1748, excavations began, and a lost world slowly emerged from the ash — streets, shops, paintings, a whole Roman town caught at a single instant. In the 1860s an archaeologist named Giuseppe Fiorelli realised that the bodies had long decayed, but had left perfect hollows in the hardened ash. By gently pouring liquid plaster into these spaces, he created casts — quiet, human shapes that record the final moments of people who had died there seventeen centuries before. Today Pompeii is a UNESCO World Heritage Site: a whole city, and the memory of an ordinary day, preserved for the world to walk through.