I'm not a geologist, vulcanologist nor even a phenomenologist but I've spent a lot of time in the last few years reading about and watching Vesuvius, mostly online or in the media, and once or twice on the spot, while writing a book on its enduring fascination.
Whether it was the birthplace of Vulcan or the nemesis of Pompeii, a favourite subject for Andy Warhol or J. M.W. Turner, a must-see for a Grand Tourist or a cheap air ticket away for the modern traveller it is - the subtitle of my book - "the most famous volcano in the world."
Even as I write, a disconsolate group of unemployed workmen are perched on a ledge, quite a few metres down the (fortunately, for now) moribund crater. They had been looking after the network of footpaths that zigzag around and up the mountain, through the National Park.
Now the cooperative that they worked for is gone, they have nothing at all and in an interview of quiet misery, their elderly spokesman told a journalist from the Repubblica website about their desperation - victims of austerity, only fortunate in being able to harness the volcano for publicity purposes. Thank goodness at this time of European crisis, Vesuvius is calm, for most of the seismologists who were monitoring it 24/7 have also lost their jobs. They spent a recent Christmas sitting on their office rooftop to draw attention to the situation; Vesuvius might have been a better choice.
Sometimes the symbolism of Vesuvius was more positive. On a May evening in 1814 Humphry Davy and Michael Faraday, towering figures of Regency science, climbed up the (erupting) cone only to find, to their surprise, a party going on. Enormous numbers of people were gathering and a feast being prepared, not just the guides' stale old trick of boiling an egg on the hot lava.
By the light of flaring torches, on fine cloths, were laid quantities of turkey, chicken, cheese and wine. God Save the Queen and Russian national songs were being sung with gusto. They learned that Napoleon had been defeated and the Neapolitans hoped the days of Joaquim Murat in Naples were numbered. Both before this date and after, countless monarchs and national leaders scrambled or were pulled up the volcano - as if it might confer some sort of blessing or, left unplacated, wreak havoc on their kingdoms or empires.
Yet since 1944 everyone has forgotten what the volcano is capable of, so unpredictable - devious when quiet, ferocious in action. The 1906 eruption broke up Thomas Cooke's funicular railway to the summit like a child throwing a tantrum a toy train set. After the catastrophe, the Italians asked to be relieved of their responsibility for the 1908 Olympics, pencilled in for Rome. Thus London came to host the Olympic Games for the first time.
The noise of rumbling and banging that the Allied forces in and around Naples heard one night in March 1944 suggested to them that Axis bombardment had begun. Having been in southern Italy since the autumn of 1943, the volcano looming over the city seemed the least of their worries. But, it turned out, Vesuvius was erupting and the mission changed in an instant into a humanitarian effort, as the lava edged down the slopes consuming everything in its slow, deadly slow, path. You can watch it in newsreel footage on YouTube, a cupola borne off a church down the mountain, the rest of the village turned into a sea of hardcore.
As so often, the villagers summoned up effigies of San Gennaro, the Neapolitan saint who has had the task of dealing with plague, disaster and (especially) volcanic eruption since medieval times.
When the phial of his blood in the cathedral fails to liquefy, a ritual that takes place with due ceremony three times a year, there is trouble ahead. In retrospect, the fact that the contents of the phial remained stubbornly solid on 16 December, 2009, as I witnessed the priests' long and ultimately fruitless vigil, should have been of concern. Little in southern Italy has gone well since. Only Vesuvius is biding its time.
Vesuvius by Gillian Darley is published by Profile Books in paperback on 24 May at £8.99Suggest a correction