History of the archaeological site
Pompei is located on a plateau (about 30 m) formed by a lava flow erupted from the Vesuvius volcano. The city dominated the valley around the Sarno River, and aroud the rivers's delta there was a busy port.
Information about the origins of the city are uncertain. The oldest available data date back to the late seventh up to the first half of the sixth century BC, when the first walls made of tuff, called 'pappamonte', were built, enclosing an area of 63.5 hectare. A 'mixed' population led to the development of the city, in which indigenous, Etruscan and Greek elements were mixed together.
At the end of the fifth century BC, the Samnites came down from the mountains of Irpinia and Sannio, settled in the plain of Campania region (that means 'fertile plain'), conquering the cities along Vesuvius and the coast and creating an alliance, whose capital was Nucèria. During the Samnite period, a great boost was given to the urbanisation process of the ancient Pompeii: the construction of a new limestone fortification for the Sarno river, following a path similar to the previous one, dates back to the fifth century BC.
At the end of the fourth century BC, under the pressure of the Samnite populations, Rome spread over Southern Italy, and between 343 and 290 BC conquered the entire Campania region. Pompeii entered as a partner (ally) in the political organisation of the Roman res publica. However, in 90-89 BC, the city, along with other Italic peoples, rebelled, claiming social and political dignity equal to Rome. Pompeii was besieged by the troops commanded by Pùblius Cornelius Sulla, and in 80 BC the city capitulated and became a Roman colony with the name of Còrnelia Venèria Pompeianòrum. After becoming a colony, it was rebuilt and enriched with private and public buildings, especially in the age of the Emperors Augustus and Tiberius, from 27 BC to 37 AD.
In 62 AD a violent earthquake struck the Vesuvius area. In Pompeii, the reconstruction began immediately, but it took long time because of the extent of the damage and the swarm that followed. Seventeen years later, on August 24th, 79 AD, the sudden eruption of Vesuvius buried Pompeii with ashes and lapillus. Today, the place still lookes like a vast building site.
The buried city was rediscovered in the 16th century, but only in 1748 the exploration phase began, under the King of Naples Charles III of Bourbon, and continued systematically throughout the ninth century up to the most recent excavations, restoration and enhancement of the ancient city, with the rediscovering of its exceptional heritage of architecture, sculptures, paintings and mosaics. The archaeological site of Pompei spreads over 66 hectares, 49 of which have been already excavated. In 1858, the director Giuseppe Fiorelli had the idea of dividing the city into regiones, or neighbourhoods, and insulae, or blocks. The names of the houses have been invented by the archaeologists over the centuries, following different criteria.

History of the excavations
The excavations started in 1748, under King Charles of Bourbon, as a way of increasing the fame and prestige of his Kingdom of the Two Sicilies.
The digging proceeded sporadically, without a well-defined plan, and only a few years later the place actually was identified as Pompeii. A part of the necropolis outside Porta Ercolano was dug up, together with the temple of Isis and part of the theatres quarter.
During the French occupation, in early 1800, there was much more activity on the site, but with the restoration of the Bourbons regime, excavations gradually slowed down again. Works were concentrated on the area of the amphitheatre and the Forum, as well as around Porta Ercolano and the theatres district. The discovery of the House of the Faun, containing the large mosaic depicting Alexander the Great in battle, caught the imagination of people all over Europe.
Following the Unification of Italy in 1861, the designation of Giuseppe Fiorelli as director marked a turning-point in the excavations process. Since then the site has been explored systematically, connecting the different areas, detailed records of the activities have been kept, and the wall paintings have been left on site, rather than being detached and taken to the museum in Naples. Fiorelli pioneered the practice of taking plaster casts to get back the image of the victims of the eruption.
Since the beginning of the twentieth century the explorations spread eastwards along the ancient town's principal streets, and more attention was paid to the remains of the upper floor of the buildings. From 1924 to 1961, the excavations were supervised by Amedeo Maiuri. This period of intense activity experienced the rediscovering of prestigious buildings, such as the Villa of the Mysteries, the complete recognition of the ancient town's perimeter, the excavation of most of the Region I and II and the necropolis of Porta Nocera, and the start of a methodical exploration of the layers below the 79 AD level, to bring to light the past of ancient Pompeii.
In recent years, excavations have been scaled down, in order to concentrate the limited resources available (not sufficient even to fulfill this goal) on restoring and maintaining the buildings which have already been exposed.