Vesuvius is well known for the huge and devastating eruption in 79 CE that buried Herculaneum and Pompeii. Archaeologists have found what people were doing at the moment of impact, and recovered the architecture of the towns. There was a bad disruption in 62 CE but the disruptions go back thousands of years. In 5960 BCE and 3580 BCE, Vesuvius had two enormous eruptions. The African plate moves northward at about one inch (2-3 cm) a year and scrapes beneath the Eurasian plate. Pliny the Younger later recorded his observations of the 79 CE event in two letters. He described the earthquakes that preceded the eruption, the eruption column, air fall, how people were affected, pyroclastic flows, and the tsunami on the sea. Volcanologists created the label "plinian" for sustained explosive eruptions that generate high altitude eruption columns and cover large areas with ash.

Among other observations, Pliny recorded that about 10 feet (3 m) of tephra fell on Pompeii, burying everything except the roofs of some buildings. The place was abandoned and even forgotten about. Digging began in 1595 but more systematic archaeological excavations took off in the mid-nineteenth century. Herculaneum was buried under 75 feet (23 m) of ash from a pyroclastic flow. About 5,000 people lived there.

Vesuvius rises up east north east of the Bay of Naples. The oldest rock from the volcano is around 300,000 years old and was probably part of the Somma volcano. After Somma collapsed around 17,000 years ago, Vesuvius started to form. The Somma Rim is to the east of the volcano, and forms a caldera-like structure. There is a nearby (15 miles/ 20 km) hook of land that sticks out which is the caldera of the Phlegraean Fields volcanic region. That caldera formed about 34,000 years ago.

Vesuvius has erupted around 36 times since 79 CE. An eruption period from 1913 to 1944 actually began in 1631. Just the lava flows have killed 3500 people adding to the slightly lower number in 79 CE. 3 million people are at risk now and some 1 million people live and work 15 minutes from a major lava flow.

An area of 31 square miles (80 square kilometres) rose up between 1983 and 1985, in places up to 5.9 feet (1.8 metres), damaging homes, the harbour, and adversely affecting the tourist industry. Up to 36,000 people were relocated.

Accurate predictions of activity are rare in vulcanology. Not every volcano is the same so monitoring must be based on experience and caution.

Volcanoes are sometimes symbolic of both natural and spiritual wars. This is the case in parts of Africa especially Western Rwanda just on the border of Lake Kivu and about 1 mile from the border of Congo, an area of fighting with a ring of volcanoes.