In 79 AD, one of the greatest natural disasters of antiquity occurred: Mount Vesuvius, located on the Gulf of Naples, erupted and buried entire cities, including the now world-famous towns of Pompeii and Herculaneum. The eruption is described particularly vividly in a letter to the historian Tacitus by the younger Pliny, whose uncle of the same name witnessed the eruption himself and died in the process (Plin. epist. 6,16,5-6):
"A cloud arose; [...] its shape must have been most like a pine tree. For it grew up as if with a giant trunk and then divided into several branches, probably because it was lifted up by a fresh current of air, but then, when this subsided, lost its buoyancy, or also because it evaporated into the breadth because of its own weight. Sometimes it was white, sometimes dirty and stained, depending on whether it had thrown up earth or ash."
In contrast to the course of the eruption, which could be reconstructed on the basis of various investigations, it has not been possible to date the eruption to the exact month. The reason for this is the tradition of the literary sources: Although Pliny mentions an exact date in his letter, this varies depending on the manuscript. In addition to the established August 24(nonum cal. Septembres), November 1(cal. Novembres), October 30(III cal. Novembres) and October 24(nonum cal. Novembres) have also been handed down. Other authors such as Cassius Dio, who only superficially mentions that the eruption occurred at the end of summer/in the fall (φθινόπωρον), also shed little light on the subject.
Archaeological finds - including autumn fruits and a silver coin of Emperor Titus, which must be dated after 8 September - support the dating of the eruption to autumn. In 2018, archaeologists discovered a graffito written in charcoal, which is assumed to have been created shortly before the eruption due to the perishable nature of the writing material. The text of the graffito reads: XVI [ante] K[alendas] Nov[embres] in[d]ulsit pro masumis esurit[ioni], roughly "On October 17, he indulged himself excessively in food". Although other readings also exist, there is a consensus among scholars regarding the date. If the above-mentioned assumption about the transience of coal is correct, this graffito would be a strong indication that Vesuvius did not erupt in August - as is often assumed on the basis of Pliny's testimony - but in all probability in October 79 AD.
P.S. To understand the Roman calendar, see the corresponding article in the Topic of the Month section from August 2023 (The Roman calendar).
Kevin Teimer
Image credit: Oil painting "The Last Days of Pompeii" by the Russian painter Karl Pavlovich Bryullov from 1830-1833.
https://de.wikipedia.org/wiki/Der_letzte_Tag_von_Pompeji_(Gem%C3%A4lde)#/media/File:Karl_Brullov_-_The_Last_Day_of_Pompeii_-_Google_Art_Project.jpg
