Eruption of Vesuvius

In 79 CE Mount Vesuvius, a volcano overlooking the Bay of Naples in southern Italy, erupted violently, burying the Roman towns of Pompeii, Herculaneum and Stabiae and many villas and farms around them. Thousands of people died. The ash and volcanic debris preserved the towns so well that their excavation, from the eighteenth century onwards, has given an unrivalled picture of everyday life in the Roman Empire.

The Campanian coast was one of the richest areas of Roman Italy, with busy towns, ports and luxurious country houses. Vesuvius had not erupted in living memory, and its slopes were covered in vineyards; few Romans seem to have recognised it as a volcano. In 62 or 63 CE a strong earthquake damaged Pompeii and Herculaneum, and repairs were still under way in 79. Smaller tremors were reported in the days before the eruption, but they were common in the region and caused little alarm.

For centuries the eruption was dated to 24 August, the date given in the surviving manuscripts of the letters of Pliny the Younger. Archaeologists had long noted evidence that seemed to fit an autumn date better, such as autumn fruits and heavier clothing. In 2018 a charcoal inscription found in Pompeii, dated to the equivalent of mid-October, appeared to confirm that the eruption happened later in the year. Many scholars now favour a date in late October 79 CE, often given as 24 October, although the question is not entirely settled.

In the early afternoon a huge column of gas, ash and pumice rose many kilometres into the sky, spreading out at the top into a cloud that Pliny compared to an umbrella pine. Wind carried the debris to the south-east, and for many hours pumice and ash rained down on Pompeii, collapsing roofs and filling streets. Many inhabitants fled at this stage. Herculaneum, to the west of the volcano, received little fall but was not spared.

During the night and the following morning, the column repeatedly collapsed, sending pyroclastic surges and flows, fast-moving avalanches of extremely hot gas and rock, down the mountain's slopes. These reached Herculaneum first, killing the people who had taken shelter in boat sheds on the shore, and later swept over Pompeii, killing those who had stayed or were trying to escape. Herculaneum was buried under around twenty metres of volcanic material, Pompeii under several metres of ash and pumice.

The only eyewitness account comes from two letters written years later by Pliny the Younger to the historian Tacitus. Pliny, then about seventeen, watched the eruption from Misenum across the bay. His uncle, Pliny the Elder, the commander of the Roman fleet there and author of a famous encyclopaedia of natural history, sailed towards the danger to investigate and to rescue people. He landed at Stabiae, where he died the next day, possibly overcome by fumes or by a medical condition.

The number of deaths is not known. Excavations have found the remains of well over a thousand people at Pompeii and around three hundred on the shore at Herculaneum, but large areas remain unexcavated and many more may have died in the countryside or while fleeing. The emperor Titus, who had come to the throne that summer after leading the siege of Jerusalem, sent officials and funds to help survivors.

The towns were largely forgotten until excavations began at Herculaneum in 1738 and at Pompeii in 1748. In the nineteenth century the archaeologist Giuseppe Fiorelli began pouring plaster into the cavities left by decomposed bodies in the ash, creating the casts that remain among the site's most striking sights. The ruins, with their houses, shops, wall paintings and graffiti, are now a UNESCO World Heritage Site, and Vesuvius, which last erupted in 1944, remains one of the most closely monitored volcanoes in the world.

Our 100 CE map shows Campania as part of the Roman Empire, two decades after the eruption.