When Vesuvius erupted on 24 August AD 79, it engulfed the two flourishing Roman towns of Pompei and Herculaneum, as well as the many wealthy villas in the area. These have been progressively excavated and made accessible to the public since the mid-18th century. The vast expanse of the commercial town of Pompei contrasts with the smaller but better-preserved remains of the holiday resort of Herculaneum, while the superb wall paintings of the Villa Oplontis at Torre Annunziata give a vivid impression of the opulent lifestyle enjoyed by the wealthier citizens of the Early Roman Empire.
Pompei was an Opician foundation of the 6th century BC, and Dionysus of Halicarnassus maintained that Herculaneum (Ercolano) was founded by Hercules on his way back to Greece from Spain. Both underwent several changes of overlord in the centuries that followed - Oscans, Samnites, Greeks, Etruscans, and finally Romans in 89 BC, following the Social War. By this time both were thoroughly Hellenized, as a result of their contacts with Greek colonies such as nearby Cumae. Pompei was elevated to the status of Colonia Cornelia Venera Pompeiana in 89 BC, whilst Herculaneum was accorded the lower rank of municipium.
Excavations have revealed the development of Pompei in particular. The original settlement, to the south-west of the Roman town, was fortified by the Samnites in the 4th century BC; these defaces were reinforced after the Roman occupation with a new wall and an interior earthen rampart. The early town had a main street (cardo) crossed by two decumani. There was a major period of urbanization in the 2nd and 1st centuries BC, when tufa replaced limestone as the main building material. At this time a triangular colonnaded forum was constructed around the ancient Doric temple in the southern part of the town, along with a theatre. Later a second forum, this time rectangular and elongated, was added with temples to the official divinities around it.
After Pompei became part of the Roman territory, it was further endowed with fine public buildings in stone, such as the large amphitheatre, the forum baths, and the odeon (small theatre) alongside the theatre. There was an episode of modernization at the end of the 1st century BC, with the construction of an aqueduct to bring the waters of the Samo River to the town, where they were distributed by means of a sophisticated supply system to houses, baths, and public fountains. High sidewalks were built along the streets, with stepping stones to facilitate crossing.
Herculaneum was a much smaller town (320m by 370m within its walls) on the coast. The latest layout, on the standard classical "Hippodamian" grid, dates from the end of the 1st century BC. The wide main street (decumanus maximus) also served as the forum, and was lined with public buildings, such as a basilica, a shrine to Hercules, a theatre, and public baths. The houses in the centre of the town were spacious, with panoramic views on the sea, which at that time came up right up to the town. There was a sacred area, with shrines and baths, outside the walls, and the surroundings contained many fine villas, such as the magnificent Villa of the Papyri.
The roles of the two towns were very different. Pompei was a commercial town, benefiting from river trade along the Samo between the interior and the coast and from that along the coastal road between Cumae and southern Campania. It was also the centre of an important wine-producing district, the other main source of its prosperity. Herculaneum, on the other hand, was a holiday resort for rich Romans from the region, with its fine views of and easy access to the sea.
The lives of both towns came to an abrupt and catastrophic end on 24 August in AD 79. The area had been shaken by an earthquake shortly before and reconstruction work was still in progress when Vesuvius erupted with tremendous violence. Pompei was buried under a thick layer of volcanic ash and stone and Herculaneum disappeared under a pyroclastic flow of many metres of volcanic mud.