Archaeologists have uncovered evidence suggesting the destruction of Pompeii may not have occurred in August of AD 79, despite what historians have believed for centuries.

The explosive eruption of Mount Vesuvius that buried the Roman cities of Pompeii and Herculaneum was thought to have taken place on 24 August that year due to the writings of Pliny the Younger, who had witnessed it.

Pliny, who lived on the other side of the Bay of Naples in Misenum, wrote to the historian and senator Tacitus that the eruption had left “a most beautiful city in ruins and destroyed so many populous cities”. His uncle, Pliny the Elder, was killed while attempting to rescue a friend in Pompeii, he said.

But fresh excavations in Pompeii have now revealed a charcoal inscription bearing the date of 17 October. This would apparently date the eruption to one week later on 24 October.

“Being charcoal, fragile and evanescent, which could not last a long time, it is more than likely that it was written in October 79 AD,” said Massimo Osanna, head of the Pompeii site.

Culture Minister Alberto Bonisoli was on hand for the announcement, where earlier this month archaeologists revealed a richly painted garden scene in a home that was unearthed during excavations of a new sector of the vast site.

Showing off the faint writing on an uncovered white wall, Mr Bonisoli hailed it as an “extraordinary discovery”.

“Today, with a lot of humility, maybe we’re rewriting the history books because we’re dating the eruption to the second half of October,” he said.

Doubt had previously been cast on the August date due to evidence relating to autumnal fruit and guides at the site tell visitors that not all historians and scientists agree on it.

Previous archaeological work had uncovered a calcified branch bearing berries that normally only come out in autumn.

The discovery of some braziers over the years also suggested the disaster did not strike at the height of summer.

At least 2.5 million people visit Pompeii each year and concerns have been raised about the integrity of the site.