CNN  — 

Newly discovered graffiti at the Pompeii archeological site could settle an old academic debate about the exact date of the Vesuvius eruption, rewriting the history of one of the ancient world’s most significant events.

Excavations in the Regio V area of the city unearthed a charcoal inscription on the wall of a room that supports the theory that the eruption occurred in October, not August of the year 79 AD, as told by history books.

While not listing a year, the graffiti reads: “XVI K Nov,” meaning the 16th day before the calends of November, or October 17 in the modern calendar.

Since charcoal is a “fragile and evanescent” material, it is very unlikely it could have been able to survive long, according to archeologists.

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Frescoes in the Criptoporticus Domus at UN World Heritage Site of Pompeii.

“It is highly probable that it can be dated to the October of AD 79, and more precisely to a week prior to the great catastrophe, which according to this hypothesis occurred on the 24th October,” the archeology team said in a statement.

Archeologists found the inscription in a house that was in the process of being renovated at the time of the eruption, so the writing would have probably been covered with plaster shortly.

“That could help explain why, next to rooms with frescoed walls and ceilings, and with cemented floors – in some cases with tiles or marble slabs – there were some areas with plastered walls or even without floors, like the atrium and the entrance corridor,” archeologists said.

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People explore the Fullonica Stephanus Domus.

Italian Culture Minister Alberto Bonisoli, who visited the site on Monday, called it “an extraordinary discovery.”

The conventional theory that the eruption took place on August 24 is because of the only eyewitness account of the event, written by Pliny the Younger 25 years later. The Roman author was 17 at the time of the eruption, which he observed from the other side of the Bay of Naples.

Previous findings of chestnuts and woolly clothing hinted at a later date for the traumatic event. The newly found graffiti might settle the debate for good.