An eruption 39,000 years ago at this site - Campi Felgrei, outside Naples - was once thought to have been a possible reason for the extinction of the Neanderthals (this hypothesis has been discarded, but that it was considered possible in the first place shows how severe the eruption was).
On another note, many contemporary religion scholars, like Elaine Pagels in her most recent book Revelations, think the CE 79 Vesuvius eruption (connected with this same site near Naples) also played into the writing of the Book of Revelation. Particularly, Rev. 8:8 - "The second angel sounded his trumpet, and something like a huge mountain, all ablaze, was thrown into the sea. A third of the sea turned into blood...."
