The release of the film, Pompeii on the 22nd February 2014 showed that the lure of the eruption of Vesuvius in 79AD remains as strong as ever. But while some may quibble about the historical accuracy of the film, few viewers would dispute its summertime setting. After all, the 24th of August is the traditional eruption date.
Or is it? For there is substantial evidence to suggest that the catastrophe occurred not in the summer but the autumn. So what is the evidence for the eruption of Vesuvius? And does it allow us to come up with a definitive date?
The Problem of the Ancient Texts
The Problem of the Ancient Texts
The eruption of Vesuvius is the earliest datable volcanic eruption on record, described in vivid detail by Pliny the Younger. Most modern translations interpret the date given by Pliny in his letter to Tacitus describing the event as the 24th August. But there are problems with this.
‘The traditional date of 24 August comes from the letter of Pliny the Younger (VI.16). The main manuscripts give ‘nonum kal. Septembres’, i.e. nine days before the Kalends or the first day of September, which on Roman inclusive reckoning is 24 August,” explained Professor Andrew Wallace-Hadrill, Director of the Herculaneum Conservation Project and an expert on Pompeii, in an interview with History and Archaeology Online. “But another principal manuscript omits the month, and a series of 15thcentury printed editions, which used manuscripts no longer surviving, give the month as November. Roman dates often were confused in the process of copying manuscripts, so we cannot be sure of the 24 August date, and there is a chance Pliny wrote 24 October. This version is supported by the histories of Cassius Dio, written a century later in Greek, who gives a long description of the eruption (book 66, 21), and dates it ‘kat’ auto to phthinoporon,’ i.e. ‘at the end of autumn.’”
Contradictions in the translations complicate matters. But intriguingly, archaeology offers supporting evidence for the October date.
Autumn Fruits and Wine: Botanical Evidence for an Autumn Eruption.
In a 2006 article for Archeo, Grete Stefani, the current site director of Pompeii described the evidence that led her and botanist Michele Borgongino to date the eruption to autumn. They analyzed the organic wares of shops and warehouses in Pompeii, Herculaneum and Oplontis, and found that they consisted of freshly harvested autumn fruits such as pomegranates and walnuts as well as dried dates, prunes and figs-typically summer fruits.
Stefani also found evidence that the vindemmia or grape harvest was over and wine production was in full swing. Wine fermenting jars called dolia were found sealed and buried at the Villa Regina, at Boscoreale. Aside from the fact that the harvest would not have occurred until September at the earliest, the wine would have been in production for at least ten days before burial. This fact, coupled with the presence of fresh autumn fruits and summer fruits already preserved suggest an autumn eruption date.
Tephra Dispersion and the Date of the Eruption
The botanical evidence is backed by that of tephra deposits for the 79AD eruption. In 2007, Stefani, along with G Rolandi, A Paone and M Di Lascio began to study the dispersal patterns of deposits of tephra-the rock fragments and ash- emitted during a series of eight eruptions of Vesuvius. For six of the outbreaks, the tephra deposits dispersed in an east-north-east direction. But for the 79AD eruption and one other, they were scattered in a southeasterly direction.
Wind data collected over a period of 20 years had established that from October to June, the prevailing wind conditions matched the northeasterly dispersal patterns of the tephra. But the southeasterly dispersal pattern associated with the 79AD eruption was more commonly associated with a transitional wind pattern prevalent as the seasons changed from summer to autumn and not the westerly blowing prevailing wind of July and August.
Although differences in modern and ancient prevailing winds must be born in mind, this suggests the 79AD eruption took place during this transitional period.
Braziers and Winter Clothes
Many of the casts of the bodies of Vesuvius’s victims showed that they were wearing layers of warmer clothing. Some have claimed that people put on heavier clothing to protect them from the eruption. But the presence of used braziers in houses such as the House of Menander suggests that the weather was much colder than would be expected in August.
Numanistics
A silver denarius minted by Emperor Titus discovered in the House of the Golden Bracelet has added further fuel to the debate. Archaeologists found the coin amongst the belongings of fugitives attempting to flee the town: a “defined and documented context’ to quote Stefani.
It is the reverse side of the coin that helps date it. Inscribed ‘TR PVIIII IMP XV COSVII PP, this describes the honours awarded to Titus: honours that can be dated.
‘COSVII’ refers to Titus’s 7thconsulship, which established the coin as 79AD. ‘TR PVIIII ‘refers to his 9thperiod of tribunical power awarded in July of that year. But it is the remaining phrase of the inscription that holds the key. ‘IMP XV refers to Titus’s 15th imperial acclamation. In two letters dated the 7thand 8th September, the emperor signs himself using the 14thimperial acclamation.
‘ This means that the eruption cannot have occurred before October 79’ explained Rosaria Ciardiello, author of ‘Some Reflections on the House of the Golden Bracelet in Pompeii’ in an interview with History and Archaeology Online.
Garum: Support for an August Eruption
But Anna Maria Ciarallo, former director of the Pompeii Applied Research lab believed that garum production in Pompeii proves the August eruption date.
“Pompeii’s last batch of garum was made with bougues, a fish that was cheap and easy to find on the market in those summer months. Still today, people living in this region make a modern version of garum, called “colatura di alici” or anchovy juice, in July when this fish abounds on the markets,” Ciarallo said in an interview with Discovery News. “Since bogues abounded in July and early August and ancient Roman recipes recommend leaving the fish to macerate for no longer than a month, we can say that the eruption occurred in late August-early September, a date which is totally compatible with Pliny’s account,”
Can we date the eruption?
Ciarallo was not alone in disputing the evidence of Stefani, Borgongino, et al- In an interview with Discovery News, Teresa Giove, a coin expert form Naples Archaeological Museum dismissed the evidence of the silver denarius as the coin was “hardly readable’. Ciarallo also countered biological evidence for an autumn eruption with some of her own.
“All pollen found in Pompeii belong to some 350 summer species. I think this is more strong evidence in favour of Pliny’s account,” she told Discover News.
But most experts now believe that the eruption date was in October. ‘Today, we don’t think that the date of the eruption was 24th August,’ Rosaria Ciardiello told History and Archaeology Online.
The reason? Quite simply because the sheer weight of evidence is in favour of October. ‘In my view,’ explained Andrew Wallace Hadrill ‘the arguments of Stefano and Borgongino are much stronger than those of Ciarallo.’
Learn more about the eruption of 79 AD, how it affected Pompeii — and how the archaeology of the site illustrates the tragic, final chapter of the city’s story in Discovering Pompeii
Sources
Pliny the Younger, Epistulae, VI, 16,
Cassius Dio, Roman History, LXVI, 21
The actual date of the eruption, Grete Stefani, “Archeo” n. 10 (260), October 2006, p. 10-13.
Some reflections on the House of the Golden Bracelet in Pompeii, Rosaria Ciardiello, 2013.
Fish Sauce Used to Date Pompeii Destruction, Rossella Lorenzi, NBC News, September 29, 2008
