POMPEII, an ancient town of Campania, Italy, near the river Sarnus, almost at the foot of Mt. Vesuvius. Its foundation was ascribed by Greek tradition to Heracles, in common with the neighbouring city of Herculaneum, but it was not a Greek colony. Strabo, in whose time it was a populous and flourishing place, tells us that it was first occupied by the Oscans, afterwards by the Tyrrhenians (i.e., Etruscans), to whom it probably owes its rectangular ground plan, and Pelasgians, and lastly, by the Samn ites. (See CAMPANIA.) No doubt, Pompeii shared the fate of the neighbouring cities, and afterwards passed in common with them under the yoke of Rome. But its name is only mentioned in cidentally during the wars of the Romans with the Samnites and Campanians only when a Roman fleet landed near Pompeii in 3o9 B.C. and made an unsuccessful marauding expedition up the river valley as far as Nuceria. At a later period, however, it took a prominent part in the Social War (91-89 B.C.), when it with stood a long siege by Sulla, and was one of the last cities of Cam pania that were reduced by the Roman arms. The inhabitants were admitted to the Roman franchise, but a military colony was settled in their territory in 8o B.C. by Sulla (Colonia Cornelia Veneria Pompeianorum), and the whole population was rapidly Romanized. Before the close of the republic many Roman nobles acquired villas in the neighbourhood, among them Cicero, whose letters abound with allusions to his Pompeian villa. The same fashion continued under the empire, and during the first century of the Christian era, Pompeii had become a flourishing place with a considerable population. In A.D. 59 a tumult took place in the amphitheatre between the citizens and visitors from Nuceria. Many were killed and wounded on both sides. The Pompeians were punished for this violent outbreak by the prohibition of all theatrical exhibitions for ten years. A painting on the walls of one of the houses represents this event.
Four years afterwards (A.D. 63) an earthquake vented its force especially upon Pompeii, a large part of which, including most of the public buildings, was either destroyed or so seriously damaged as to require to be rebuilt. The inhabitants were still actively
engaged in repairing and restoring it, when the whole city was overwhelmed by the great eruption of Vesuvius (q.v.), A.D. 79. Pompeii was merely covered with a bed of lighter substances, cinders, small stones and ashes, which fell in a dry state, while at Herculaneum the same substances, being drenched with water, hardened into a sort of tufa, which in places is 65 ft. deep. The whole of this superincumbent mass, attaining to an average thick ness of from 18 to 20 ft., was the product of one eruption, though the materials may be divided generally into two distinct strata, the one consisting principally of cinders and small volcanic stones (called in Italian lapilli), and the other and uppermost layer of fine white ash, often consolidated by the action of water from above so as to take the moulds of objects contained in it (such as dead bodies, woodwork, etc.), like clay or plaster of Paris. It was found impossible to rebuild the town, and its territory was joined to that of Nola. But the survivors returned to the spot, and by digging down and tunnelling were able to remove all the objects of value, even the marble facing slabs of the large build ings.
In the middle ages, however, the very site was forgotten. Ruins and inscriptions were found by the architect Domenico Fontana in making an underground aqueduct across the site in 1594-1600, but only in 1748 a more careful inspection of this channel re vealed the fact that beneath there lay entombed ruins far more accessible than those of Herculaneum. Only in 1763 systematic excavations were begun; the work, which had received a vigorous stimulus during the period of the French government (1806-14), was prosecuted under the Bourbon kings (1815-61). Since 1861 it has been carried on under the Italian government on a system devised by G. Fiorelli, according to which the town is for con venience divided into 6 or 9 regions, which are subdivided into insulae (blocks), the gates, streets and houses being also named for convenience, though often incorrectly.