The Forum of Nerva, the fourth and smallest of the imperial fora, was built by Emperor Domitian prior to 85 CE and officially opened by Nerva in 97 CE. It was constructed on the site of a street called the Argiletum, which had been a popular market area for booksellers and cobblers. The new forum served as both a main street and a grand entrance to the other Roman Fora.

The layout of the Forum of Nerva is elongated and narrow, with columns jutting out from the walls as decoration rather than arcades. A temple dedicated to the goddess Minerva stood prominently at the western end, and behind it was a grand entrance.

After the fall of the Western Roman Empire, the region returned to a marshy state. In the ninth century CE, several houses were constructed on the site using materials scavenged from the ruins. The temple of Minerva remained mostly intact until it was taken down by Pope Paul V in 1606 CE to be used for the Acqua Paola fountain on the Janiculum and the Borghese chapel at Santa Maria Maggiore.

The eastern end of the complex was uncovered through archaeological excavations from 1926 to 1940 CE, however, parts of the excavations were later destroyed during the construction of the Via dei Fori Imperiali. In the late 1990s, more archaeological work was conducted at the site.

circa 97 CE

Temple of Minerva
During the turbulent times comprised between 85-95 CE, the area (today known as the Forum of Nerva) located between the Forum of Caesar and the Forum of Augustus (north) and the Forum of Peace (south) underwent several transformations and was finally monumentalized by the construction of a fourth forum by the emperor Domitian (circa 81-96 CE). Domitian was murdered in 96 CE and the Forum was inaugurated in the year 97 CE by his successor Nerva (96-98 CE) who completed the construction and from which the Forum took its name.

circa 97 CE

Colonnacce
The long and narrow space available for the new forum did not allow the planning of porticoes which were replaced by colonnades and trabeation projecting inwards from the outer wall. Out of these colonnades, probably made up of fifty columns, only two columns (inspect) survuve today. These remaining columns are commonly called "colonnacce" for their ruined appearance. The columns were made of Pavonazzetto marble (from modern day Turkey and typically displaying purple veins agains a white background). Above the projecting colonnade, metopes depicting the people that lived in the Empire decorated the attic. One of these, which used to be interpreted as representing Minerva (inspect), can be seen today in its original position above the Colonnacce. It has been recently identified as the personification of the Pirusti, an ancient population of the Balkan Peninsula (fragments of another similar figure are on display in theMuseum of the Imperial Fora).

The frieze on the trabeation displayed stories of deities as it can be seen from the preserved section where the myth of Minerva is depicted. The Temple of Minerva was embedded in the centre of the short eastern side of the Forum. It had six columns on the facade and an uncommonly downward tilted tympanum. During the Middle Ages the temple was occupied by a two story structure. It survived in a good state of preservation until 1606 CE when Pope Paul V (1605-1621 CE) demolished it completely to employ the marble as construction material elsewhere.