The Forum of Aquileia was a square, the beating heart of the political, administrative and social life of the city. Its first phase dates back to the 2nd century BC.

In the first half of the 1st century AD. it took on the appearance that can still be seen today, with the arcades that surrounded it on at least three sides.

To the east and west, numerous shops overlooked the portico. To the south, along the entire width of the square, the civil basilica developed. The layout of the north side is almost completely unknown, except for a circular building with steps, which identifies the Comitium for popular meetings, from the Republican age.