Have you heard of Herculaneum?

If you have, you might know it was quite close to Pompeii. You may also be aware that it suffered destruction at the same time as its famous neighbour in 79 AD.

But would you know much more? The larger Pompeii — glamorised with its brothels, bars, amphitheatre — and the tragic casts of its former citizens– tends to overshadow Herculaneum.

Which is an injustice, for this small, seaside town, popular as a summer retreat for holidaying Romans is no less spectacular, fascinating– or tragic. And like Pompeii, the story of how Herculaneum was destruction lies preserved in its archaeology.

The Eruption Begins

Herculaneum lay only 4.5 miles northwest of Vesuvius. But surprisingly, the start of the volcano’s eruption did not affect it as severely as nearby Pompeii. 

True, alarming tremors would have shaken the town and plunged it into blackness as the 33 km high eruption column over-shadowed it. But there is an absence of lithics in the archaeological layer belonging to this early stage of the eruption, showing the southwards direction of the stratospheric winds kept the rain of lapilli and small balls of volcanic ash that plagued Pompeii away from Herculaneum.

This absence of volcanic debris meant that the roads around the town remained clear —allowing anyone who was sufficiently alarmed by events to flee.

The Pyroclastic Surges

Whereas Pompeii’s destruction was drawn out, Herculaneum’s was sudden and decisive.

In the early hours of the second day of the eruption, Vesuvius’s eruption column collapsed under its own weight, releasing clouds of hot gases, dry, heated ash and rock fragments — collectively known as a pyroclastic surge.

Pliny the Younger, who witnessed the eruption from across the bay at Naples at Misenum, described one such surge as: “a fearful black cloud, rent by forked and quivering bursts of flames” that “sank down to the earth and covered the sea.”

At between midnight and 1 am, the first of these surges left Vesuvius, and travelled at 68 mph towards Herculaneum.

The Effects of the Surge: Carbonisation

Within three to four minutes of arriving at the walls of Herculaneum, the first surge covered the town. It blasted its way over buildings and through streets, its high pressure forcing fine ash into the smallest nooks and crannies, coating Herculaneum in a grey shell.

Scientists compared analyses of the macroscopic, microscopic and ultrasonic features of the bones found at Herculaneum to modern bones heated to a range of temperatures consistent with pyroclastic surges.

As a result, anthropologist Pier Paolo Petrone has concluded that the first surge to hit Herculaneum was at least 500 degrees Celsius. Such temperatures meant that not only life in Herculaneum was in danger, but the very fabric of the town.

At this temperature, the surge should have incinerated anything organic in its path. But paradoxically, the ash now coating Herculaneum also protected it against these temperatures. It caused the superheating of any food, wood or leather it encased and carbonised — so it was preserved instead of destroyed. This is why furniture, food — even window and doorframes —survive in their actual rather than as casts in Herculaneum.

Violent Demolition of Buildings

The second effect of the subsequent surges was to rip off roofs and smash the walls of buildings with such a force that they were depositing some distance from their original location.

The second surge — which followed minutes after the first — was particularly destructive. Archaeologists discovered a whole roof, complete with beams, rafters and roof tiles deposited upside down on the beach below the seaside terrace of Herculaneum.

The Burial of Herculaneum

Following in the wake of this destruction was the volcanic flow, a volcanic mud mixed with fragments from Herculaneum’s buildings. It buried the town under 23-25 metres of material.

The maximum depth of flow occurred along the seashore, where the flow halted as it began to cool, resulting in a “back up” of material. Such was the build-up of debris along the shoreline that it pushed the seafront of Herculaneum out some 400 metres further.

The People of Herculaneum

But what of the people? Did they take their chance to escape in the early stages of the eruption?

Initially, archaeologists believed they did. Excavations of residences revealed only around 30 bodies of people who for one reason or another, could not leave. Amongst them was a baby left in its crib in the House of the Mosaic Atrium, a sickly young boy trying to hide under his bed in a gemstone workshop, and a man, asleep in his room in the Collegium Augustalium

Then, in 1981, excavations around the former seafront revealed human remains. More excavations followed in 1982, resulted in the discovery of more bodies on what had been Herculaneum’s beach and the remains of a capsized boat.

Later that year came the most astonishing discovery of all: the excavation of a series of rooms or fornici in the retaining wall at the base of the Suburban Baths. These fornici may have been warehouses or boat stores for the harbour. But they were also the last refuge for a sizable portion of the population of Herculaneum. In all, experts have found 296 skeletons (not counting the 59 bodies on the beach)— each arch sheltering several dozen people.

Cause of Death in Herculaneum

Ash may have protected wood from the extremes of the first surge’s temperatures. The people of Herculaneum were not so lucky.

Dr Petrone, an expert involved in research into the remains of Vesuvius’s victims in both Pompeii and Herculaneum, explained to History and Archaeology Online the tell-tale signs that the people of Herculaneum died from the heat of the surge:

‘Evidence of the corpses exposure to high temperature, apart from postures, were the explosion of the skulls, gross and micro cracking of bones and teeth, blackening of the bones less protected by soft tissues, hyper flection of hands and feet,’ he said.

Death in Herculaneum’s Boatsheds

It seems that the people may have fled to the boat sheds because of the earth tremors. According to Professor Andrew Wallace-Hadrill in his book “Herculaneum: Past and Future,” the concrete arches served as the perfect place to shelter during an earthquake. They were, however, not much protection against pyroclastic surges.

The vaults may have offered a degree of shelter. But the skeletons of the victims’ show that they died of thermal shock as the surge hit. Their blackened bones and bent limbs due to muscular contractions are both evidence of extreme heat. Death, fortunately, would have been instantaneous.

…And on the Beach

Escape by sea by the time the surges his Herculaneum was hopeless. In Misenum, Pliny describes how “the sea sucked away…apparently forced back by the earthquake: at any rate, it receded from the shore, so that quantities of sea creatures were left stranded.”

Yet it seemed at the time of the surge, 59 people in Herculaneum may have attempted to escape by the sea — and venturing onto the beach left them exposed to the superheated cloud boiling towards them.

The force of the surge hurled them to the ground. The bodies of many skeletons found on the beach have breakages, caused by the power and impact of the surge. But at the same time, the searing temperatures ignited hair, clothing and flesh causing instant death, vaporising soft flesh and tissues.

So intense was this heat, that in some cases, skulls have been found, red-stained from where the high temperatures caused their brains to expand and split from the subsequent explosion.

The Value of Herculaneum

Ash from the pyroclastic flow quickly replaced the flesh of these bodies. Today only the skeletons remain – unlike at Pompeii, where the unique conditions of the disaster caused impressions of the bodies of the eruption’s last victims to form “casts”.

But while the remains of Herculaneum’s citizens may not be as visually dramatic as Pompeii, analysis of their bones offers essential insights into Roman life.