From across the Bay of Naples, a seventeen-year-old named Pliny the Younger watched a cloud rise from Mount Vesuvius that he later compared to an umbrella pine: a towering trunk of ash spreading into branches high in the sky. His uncle, Pliny the Elder — admiral of the Roman fleet at Misenum and author of an encyclopaedic Natural History — ordered ships launched, first out of scientific curiosity, then as a rescue mission when desperate messages arrived from the shore. The elder Pliny landed at Stabiae, tried to calm his hosts by bathing and dining as ash fell, and died on the beach the next day, probably overcome by the volcanic fumes and exertion. His nephew's two letters to the historian Tacitus, written decades later, are the only surviving eyewitness account — and the reason vulcanologists still call this type of explosive, column-forming eruption "Plinian."
The people living around the mountain in AD 79 did not really know Vesuvius was a volcano; it had been quiet for centuries, its slopes covered in vineyards. There had been warnings they could not read: a serious earthquake in AD 62 or 63 had damaged Pompeii badly enough that parts of the town were still being repaired seventeen years later, and tremors were common enough that summer that people shrugged them off.
Two towns, two deaths
Pompeii, a prosperous commercial town of perhaps 10,000 to 12,000 people, stood downwind. For roughly eighteen hours, pumice and ash rained on it, accumulating metres deep, collapsing roofs and driving most of the population to flee — those early hours are why the majority escaped. Then the eruption column collapsed, and the real killers arrived: pyroclastic surges, avalanches of superheated gas and ash flowing down the mountain at enormous speed. The surges killed everyone still in Pompeii, and the remains of well over a thousand victims have been found in the town.
Herculaneum, a smaller and wealthier seaside town, sat upwind and escaped the pumice rain, but the surges reached it first and buried it far deeper — around twenty metres of volcanic material that turned hard as rock. For centuries scholars believed almost all its inhabitants had escaped, until excavations in the 1980s uncovered some 300 skeletons huddled in the boat chambers along the ancient waterfront, waiting for a rescue by sea that never came. The extreme heat at Herculaneum carbonised wood, food and papyrus scrolls, preserving organic material that rotted away everywhere else — including an entire library of charred scrolls from the so-called Villa of the Papyri, which researchers are still trying to read.
Even the eruption's date is a live question. The traditional date, from copies of Pliny's letters, is 24 August. But excavated evidence — autumn fruits, braziers in use, and most strikingly a charcoal graffito found in 2018 apparently written in mid-October of that year — has convinced many archaeologists the eruption actually happened in the autumn of AD 79.
The town that taught us daily life
Pompeii slept under its ash blanket, looted a little and then largely forgotten, for nearly seventeen centuries. Herculaneum was rediscovered first, by well-diggers, with formal excavations from 1738 under Charles of Bourbon, king of Naples; Pompeii followed in 1748. What emerged changed Europe's imagination — Grand Tourists flocked, and the finds helped fuel the neoclassical craze in art and design.
What makes Pompeii unique is not temples or treasure but the texture of ordinary life, preserved mid-moment. Loaves of bread, stamped by the baker, were found carbonised in ovens. Fast-food counters — thermopolia — still held jars sunk into their marble tops. Election slogans and thousands of graffiti cover the walls: advertisements, insults, love notes, gladiator fan-boasts. The house of a merchant who made garum, the ubiquitous Roman fermented fish sauce, advertised his product in mosaic. And in 1863 the excavation director Giuseppe Fiorelli introduced the technique that produced the site's most haunting images: pouring plaster into the hollows left in the hardened ash where bodies had decayed, casting the victims — adults, children, even a chained dog — in their final positions.
Vesuvius, meanwhile, remains one of the most dangerous volcanoes on Earth, not because of its size but because of its neighbours: millions of people live in the greater Naples area within its reach. It last erupted in 1944, during the Allied occupation of southern Italy. The mountain is not extinct; it is waiting.
Quiz nuggets
- Pliny the Younger's letters to Tacitus are the only eyewitness account; "Plinian" eruptions are named after him.
- Pliny the Elder, commander of the fleet at Misenum, died at Stabiae during a rescue attempt.
- Pyroclastic surges, not lava, killed the victims of Pompeii and Herculaneum.
- Giuseppe Fiorelli began making plaster casts of victims' body cavities in 1863.
- Vesuvius last erupted in 1944, during the Second World War.