Pompeii's biggest mystery: when exactly did Vesuvius erupt?

The destruction of Pompeii when Mount Vesuvius erupted is one of antiquity's best-known disasters. Even so, as HistoryExtra reports, the exact date on which the city was buried under ash remains a live debate among historians and archaeologists.

The traditionally accepted date is known as 24 August in the year AD 79. That date rests largely on the letters of the Roman writer Pliny the Younger, who described the event years later; but differences in the surviving copies of these texts call the date's certainty into question.

In recent years, archaeologists have put forward evidence that an alternative date, namely autumn (often October), is more likely. This view rests on various findings in the remains and challenges the traditional summer date.

One of these pieces of evidence is seasonal food remains uncovered in excavations. Findings such as ripened pomegranates and figs left out to dry point to autumn, because these products are usually harvested at the end of summer.

Similarly, traces of thicker, warmer clothing in some remains strengthen interpretations that the event took place not in the summer heat but in a cooling season. Such everyday-life details provide valuable clues for archaeologists.

Coins are also at the centre of the debate. It has been argued that inscriptions on some of the coins found in the remains point to a period after the traditional August date. However, the dating and interpretation of coins is open to differing assessments among experts.

One of the most striking findings is a piece of graffiti written in charcoal. Given that such temporary writing is thought not to last long, the writing having been made at a date close to the eruption, along with the date information on it, is presented as important evidence supporting the autumn thesis.

Historians stress that in debates of this kind no single piece of evidence is decisive. Bringing together different sources, written texts, archaeological findings and scientific analyses, is presented as the way to build a more reliable picture of the past.

Thanks to the protective effect of the volcanic ash, Pompeii offers a unique window onto the daily life of ancient Rome. For that reason, every new finding about the city deepens not just a debate over a date but also our understanding of life in the period.

In the end, the exact date of the eruption has not been settled; but the debate itself is an instructive example of how the discipline of history weighs evidence and reassesses accepted narratives in the light of new findings. (Interpretive conclusions are attributed to the historians and archaeologists concerned.)