The Forum was born from a market place at the cross of regional commercial roads, and became the center of the small city (VII - VI centuries B.C.); it reached its actual dimensions in the V century B.C.. The Forum was the center of religious, political and economic life of Pompeii. At the end of the rectangular square (143 X 38 m.) lies the Temple of Jupiter, framed on two sides with commemorative arches with fountains. Surrounding three of its sides are two storied porticos with travertine columns. A few tufa columns on the south side bear witness to a more ancient phase of the Forum, dating from perhaps the first decades of the first century B.C..
The ancient paving made of large slabs of travertine marble was pillaged after the eruption along with statues, some of which were equestrian, dedicated to famous imperial personalities and illustrious Pompeians. Administrative and political offices, such as the Office of the Mayors (duoviri) and the Office of the Ædiles (or municipal chairmen), were placed in front of the temple. The broad sides of the Forum had on the east the Comitium (the electoral seat), cloth and food markets along with edifices for the imperial cults, while on the western side were the prison, latrine, granaries, weights and measures office, and Basilica.