Pompeii, unlike the other towns in Campania founded for the most part by Greek colonists, was built by the Oscans, probably around the 9-8th century B.C., even if the evidence now available does not go back beyond the 6th century. The town developed on lava terracing formed many centuries earlier.

It constituted an important natural defence against the threat of invasion by neighbouring peoples. At the same time the volcanic nature of the land meant the territory of the Sarno valley was particularly fertile, thereby allowing for the rapid development of the agricultural economy.

Pompeii soon made contact with the nearby Greek colonies, whose culture, way of life and the religion of Magna Graecia it quickly absorbed. Evidence of this is to be found in the shape of the Doric temple which stands in the Triangular Forum. The city was subject to the Etruscans for almost fifty years (until 474 B.C.) when the latter occupied part of inland Campania. Immediately afterwards it came back under the Greek sphere of influence.