Mount Vesuvius famously erupted in AD 79, traditionally dated to August 24. This catastrophic eruption destroyed the Roman cities of Pompeii and Herculaneum. The eyewitness account by Pliny the Younger, written about 25 years after the event, indicated the eruption began on August 24, a date widely accepted for centuries. However, recent archaeological findings have challenged this traditional date. An inscription discovered in Pompeii, dated to mid-October (October 17 in modern calendar), along with evidence such as autumnal fruit and heating braziers found in the ruins, strongly suggest that the eruption may have occurred later than August. Some researchers now propose the eruption happened in late October, possibly on October 24, AD 79. The eruption lasted about two days, beginning with a high column of ash and pumice followed by deadly pyroclastic flows that buried the cities. The eruption released enormous thermal energy, far exceeding that of atomic bombs, and remains one of history's deadliest volcanic events. In summary, while August 24 was long considered the eruption date based on Roman historical accounts, compelling recent evidence supports a revised date in late October 79 AD.