According to the Smithsonian Institution, 1,511 above sea volcanoes have been active over the past 10,000 years with 539 of them erupting one or more times during written history. Perhaps the most famous of these was in 79 CE when Vesuvius completely destroyed Pompeii and Herculaneum and surrounding towns.

Long thought extinct, Vesuvius suddenly returned to life on August 24, 79 CE, erupting with violence. Flames from the volcano soared high into the sky and was soon followed by an immense black cloud. Volcanic matter rained down on Pompeii which caused the roofs and walls to collapse and after three days a layer of ash, rock, mud and lava in depths of up to 15 to 20 feet covered Herculaneum.

A vivid eyewitness account of the eruption is preserved in two letters written by Pliny the Younger to the historian and close friend, Tacitus. The letters were written in response to a request by Tacitus for information about the death of Pliny the Elder who was the commander of the Roman fleet at Misenum at the time and died at Stabiae when he rushed to help the stricken population and get a closer view of the volcanic eruption.

Brief History of Pompeii

First settled by Oscan descendants of the Neolithic inhabitants of Campania, archaeological evidence indicates that the village of Pompeii soon came under the influence of the cultured Greeks who had settled across on the other side of the mouth of the Sarnus River in the 8th century BCE. The Etruscans arrived in Campania in the 7th century and immediately challenged the Greek influence in the region. Their influence remained strong until they too were ousted by the Saminites who in turn were defeated by the Romans in 310 BCE. At that time, Pompeii became a part of the emerging Roman state.

Pompeii joined the Italic revolt against Rome in the Social War of 91-87 BCE. Though the city wasn't destroyed it lost all trace of autonomy and became a colony called Colonia Vernia Cornelia P in honor of its conqueror, L. Cornelius Sulla.

It grew from a modest farming town to an important industrial and trading center. Luxury services, trade with foreign countries and agriculture were developed. As Rome herself became more prosperous, her citizens began to look up on Pompeii as a luxury resort and soon luxury country homes of the most powerful people in the world began to hug the shoreline. In 62 CE, the first great natural disaster hit Pompeii in the form of an earthquake. The citizens began rebuilding and restoring the industrial and commercial activities, using the opportunity to expand and reshape the Forum including realigning the streets, uniting building fronts and adding a new building based on the latest designs from Rome. However, it had not yet recovered from the earthquake when final destruction came 17 years later. In fact, in his letter to Tacitus, Pliny writes of the region:

It is true that he [Pliny the Elder] perished in a catastrophe which destroyed the loveliest regions of the earth, a fate shared by whole cities and their people.....

In the summer of 79 CE, Pliny and his mother were living at the home of her brother, Pliny the Elder. When Vesuvius erupted, Pliny the Younger was at Misenum, about 20 miles across the bay from the center of the eruption. Even so, his chances of survival were not good. While some of his actions may not appear judicious, what counts is that he survived and left us with as accurate a representation of the events as we could ever hope to have.

Pliny and his mother at Misenum

The First Letter

My uncle was stationed at Misenum, in active command of the fleet. On 24 August, in the early afternoon, my mother drew his attention to a cloud of unusual size and appearance. He had been out in the sun, had taken a cold bath, and lunched while lying down, and was then working at his books. He called for his shoes and climbed up to a place which would give him the best view of the phenomenon. It was not clear at that distance from which mountain the cloud was rising (it was afterwards known to be Vesuvius); its general appearance could be expressed as being like an umbrella pine, for it rose to a great height on a sort of trunk and then split off into branches, I imagine because it was thrust upwards by the first blast and then left unsupported as the pressure subsided, or else it was borne down by its own weight so that it spread out and gradually disbursed. Sometimes it looked white, sometimes blotched and dirty, according to the amount of soil and ashes it carried with it. My uncle's scholarly acumen saw at once that it was important enough for a closer inspection, and he ordered a boat to be made ready, telling me I could come with him if I wished. I replied that I preferred to go on with my studies, and as it happened he had himself given me some writing to do.

The eruption of Vesuvius came in two separate stages and here Pliny describes the first stage which has since become known as the 'Plinian' phase. During this phase, the material (called tephra) is ejected in a tall column, forming a 'mushroom cloud' and then falling to earth like rain. It has been estimated that the Plinian column on that infamous day in August reached heights of approximately 66,000 feet high. [Haraldur Sigurdsson, 1982, 1985] The subsequent rain of ash and pumice covered a broad area predominantly to the south of Vesuvius and was carried by the prevailing winds. This phase lasted approximately 18 hours and it is reasonable to assume that any timber roof structure would have collapsed under the full weight of the pumice layer.

What was originally to be a scholarly inquiry became far more serious. As Pliny the Elder was leaving, he was handed a desperate message from a woman he knew living at the foot of the mountain. He ordered the fleet into action and boarded one of the vessels to personally direct the rescue operation. We take up Pliny's description of the eruption from this point:

He hurried to the place which everyone else was hastily leaving, steering his course straight for the danger zone. He was entirely fearless, describing each movement and phase of the portent to be noted down exactly as he observed them. Ashes were already falling, hotter and thicker as the ships drew near, followed by bits of pumice and blackened stones, charred and cracked by the flames: then suddenly they were in shallow water, and the shore was blocked by debris from the mountain. For a moment my uncle wondered whether to turn back, but when the helmsman advised this he refused, telling him that Fortune stood by the courageous and they must make for Pomponianus at Stabiae. [Four miles south of Pompeii] He was cut off there by the breadth of the bay (for the shore gradually curves round a basin filled by the sea) so that he was not as yet in danger, though it was clear this would come nearer as it spread. Pomponianus had therefore already put his belongings on board ship, intending to escape if the contrary wind fell. This wind was of course full in my uncle's favor, and he was able to bring his ship in. He embraced his terrified friend, cheered and encouraged him, and thinking he could calm his fears by showing his own composure, gave orders that he was to be carried to the bathroom. After his bath, he lay down and dined; he was quite cheerful, or at any rate he pretended he was, which was no less courageous.

Meanwhile on Mount Vesuvius broad sheets of fire and leaping flames blazed at several points, their bright glare emphasized by the darkness of night. My uncle tried to allay the fears of his companions by repeatedly declaring that these were nothing but bonfires left by the peasants in their terror, or else empty houses on fire in the districts they had abandoned. Then he went to rest and certainly slept, for as he was a stout man his breathing was rather loud and heavy and could be heard by people coming and going outside his door. By this time the courtyard giving access to his room was full of ashes mixed with pumice stones so that its level had risen, and if he had stayed in the room any longer he would have never gotten out. He was wakened, came out and joined Pomponianus and the rest of the household who had sat up all night. They debated whether to stay indoors or take their chance in the open, for the buildings were now shaking with violent shocks, and seemed to be swaying to and fro as if they were torn from their foundations. Outside on the other hand, there was the danger of falling pumice-stones, even though these were light and porous; however, after comparing the risks they chose the latter.......

Elsewhere there was daylight by this time, but they were still in a darkness, blacker and denser than any ordinary night, which they relieved by lighting torches and various kinds of lamps. My uncle decided to go down to the shore and investigate on the spot the possibility of any escape by sea, but he found the waves still wild and dangerous. A sheet was spread on the ground for him to lie down, and he repeatedly asked for cold water to drink. Then the flames and the smell of sulphur gave which gave warning of the approaching fire drove the others to take flight and roused him to stand up. He stood leaning on two slaves and then suddenly collapsed. I imagine because the dense fumes checked his breathing by blocking his windpipe which was constitutionally weak and narrow and often inflamed. When daylight returned on the 26th - two days after the last day he had seen - his body was found intact and uninjured, still fully clothed and looking more like sleep than death.

The younger Pliny and his mother tried to carry on a normal routine during this time. He continued his lessons for the remainder of the day, bathed, dined and retired. He records that he fell into a fitful and uncomfortable sleep. The earthquakes continued and became so violent throughout the night that he and his mother both arose and sought each other for comfort. To allay his fears and those of his mother's, Pliny resumed his studies, writing later "I don't know whether I should call this courage or folly on my part (I was only seventeen at the time) but I called for a volume of Livy and went on reading as if I had nothing else to do."

One of his uncle's friends, recently returned from Spain, urged them to flee immediately and chastised them for what he considered their foolish behavior. Unplussed, Pliny states "I remained absorbed in my book."

At daybreak, they realized the house may collapse around them and they finally only then decided to flee but that brought on additional problems. He describes how they were followed by a panic stricken mob of people who hurried them on their way.

By the morning of August 25, all the covered buildings in Pompeii were uninhabitable as a result of the collapsed floors and roofs. It appears that there was a mass exodus from the city as only approximately 2,000 of her estimated 20,000 residents have been found in excavations and the majority of these are above the pumice layer.

The Second Letter

It is now, in his second letter to Tacitus, that he begins to describe the second phase of the eruption, the Peléan phase where material flowed down the sides of the of the volcano as fast moving avalanches of gas and dust, called pyroclastic flow (pyroclasts are rock fragments formed by a volcanic explosion or ejected from a volanic vent). The term Peléan comes from the eruption of Mount Pelée on the island of Martinque where the phenomenon was first documented.

The Peléan phase brought a much more damaging eruption, in the form of high temperature avalanches of dust and gas hugging the ground at high velocity. There are several terms to describe the various aspects of this type of eruption and the two broad categories as defined by Sigurdsson are:

Pyroclastic Flow: A hot, chaotic avalanche of pumice, ash, and gasses. Pyroclastic flows can move at high speeds along the ground and pass over substantial objects. Their distribution is strongly controlled by topography.

Pyroclastic Surge: A turbulent cloud of volcanic ash and hot gasses, which hugs the ground and travels at speeds often exceeding 100 km per hour. Surge deposits are more widely distributed than pyroclastic flow deposits though not as widespread as air fall pumice layers.

Both aspects described above are extremely rare and have only recently been documented. Sigurdsson has analyzed the data as well as the soil surveys. Pyroclasts are identified in the geologic strata as thin, black layers. The eruption of Vesuvius in 79 AD is unique in that there are no less than six such layers indicating that there was at least six pyroclastic surges. The fourth and fifth such flows reached Pompei and it is here, in this level that we see the majority of the victims. This discovery forced scientists to revise their theory regarding the cause of death. Earlier, they had surmised that most of the victims died as a result of the falling ash and suffocated. The sixth and last pyroclastic surge was the strongest and the most far reaching, reaching areas far outside of Pompeii and, as a result, in Sigurdsson's opinion, it is possible the death toll from the eruption is far greater than originally surmised.

Pliny's uncle's friend had stayed close and he again encourages them to leave. Pliny and his mother are understandably reluctant to leave the area without some word about Pliny's situation and hesitate. Their friend choses to look to his own safety and leaves. It is now that the most terrifying moments of the eruption come:

Soon afterwards the cloud sank down to earth and covered the sea; it had already blotted out Capri and hidden the promontory of Misenum from sight. Then my mother implored, entreated and commanded me to escape as best I could - a young man might escape whereas she was old and slow and could die in peace as long as she had not been the cause of my death too. I refused to save myself wihout her and grasping her hand forced her to quicken her pace. She gave in reluctantly, blaming herself for delaying me. I looked round; a dense black cloud was coming up behind us, spreading over the earth like a flood. "Let us leave the road while we can still see," I said, "Or we shall be knocked down and trampled underfoot in the dark by the crowd behind." We had scarcely sat down to rest when darkness fell, not the dark of a moonless or cloudy night, but as if the lamp had been put out in a closed room. You could hear the shrieks of women, the wailing of infants, and the shouting of men; some were calling their parents, others their children or their wives, trying to recognize them by their voices. People bewailed their own fate or that of their relatives and there were some who prayed for death in their terror of dying. Many besought the aid of the gods, but still more imagined there were no gods left, that the universe was plunged into eternal darkness for evermore. There were people, too, who added to the real perils by inventing fictitious dangers; some reported that part of Misenum had collapsed or another part was on fire, and though their tales were false they found others to believe them. A gleam of light returned, but we took this to be a warning of the approaching flames rather than daylight. However, the flames remained some distance off; then darkness came once more and ashes began to fall again, this time in heavy showers. We rose from time to time and shook them off, otherwise we should have been buried and crushed beneath their weight. I could boast that not a groan or cry of fear escaped me in these perils, had I not derived some poor consolation in my mortal lot from the belief that the whole world was dying with me and I with it.

At last the darkness thinned and dispersed into smoke or cloud; then there was genuine daylight, and the sun actually shown out, but yellowish as it is during an eclipse. We were terrified to see everything changed, buried deep in ashes like snowdrifts. We returned to Misenum where we attended our physical needs as best we could, and then spent an anxious night alternating between hope and fear. Fear predominated, for the earthquakes went on, and several hysterical individuals made their own and other people's calamities seem ludicrous in comparison with their frightful predictions. But even then, in spite of the dangers we had been through and were still expecting, my mother and I had had still no intention of leaving until we had news of my uncle.

The Legacy

Pompeii remained buried under a layer of pumice and ash 19 to 23 feet deep until it was rediscovered in the 16th century by architect Domenico Fontana. The city's sudden burial served to protect it from vandalism, looting and the destructive effects of weather. Herculaneum was discovered in 1709 and excavations there began in 1738 with work beginning in Pompeii ten years later. The work at these sites in the mid 18th century marked the start of modern archaeology.

Although a quarter of Pompeii remains unexcavated, it affords a wealth of information about everday life in Roman times for researchers and visitors alike. The remarkable preservations of the commercial buildings, the homes, the art, the architecture and even the people themselves, present the modern world with an unprecedented and unparallelled look at the details of life in an ancient Roman town.

The Letters of the Younger Pliny, translated by Betty Radice, Penguin Books, 1969

Melting the Earth: The History of Ideas on Volcanic Eruptions, Haraldur Sigurdsson, Oxford University Press, 1999

Roman People: Second Edition, Robert B. Kedric, Mayfield Publishing Company, 1993

Egypt, Greece and Rome: Civilizations of the Ancient Mediterranean, Charles Freeman, Oxford University Press, 1996

The Oxford History of the Classical World, Edited by John Boardman, Jasper Griffin, Oswyn Murray, Oxford University Press, 1986

Graphic courtesy of M. Houk and is copyrighted. The volcano is suffering acute indigestion because of its most recent and unsuccessful sacrifice