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

Domitianic Origins
The Forum of Nerva, also known in antiquity as the Forum Transitorium, was initiated under Emperor Domitian (reigned 81–96 CE) as the final link in the series of imperial fora constructed in central Rome. The area chosen for the forum lay between the Forum of Augustus and the Forum of Vespasian, adjacent to the Argiletum, a vital thoroughfare connecting the Subura district to the Roman Forum. Due to the narrow and irregular constraints of the site—already flanked by existing monumental architecture—the forum had to be fitted into a tight space, resulting in a long, narrow rectangular plan.

Domitian began construction as part of his broader urban renewal program and his effort to monumentalize the city after the damage caused by the fires of 80 CE. However, Domitian was assassinated before the forum was completed or dedicated.

Nerva’s Completion and Dedication
The forum was completed and formally inaugurated in 97 CE by his successor, Emperor Nerva. To dissociate the project from Domitian’s unpopular legacy—he was damnatio memoriae by the Senate—Nerva claimed credit for its completion, and the structure came to bear his name officially, although "Forum Transitorium" remained a widely used contemporary designation.

The forum primarily served as a passageway rather than a large civic or ceremonial space, as implied by the term transitorium ("thoroughfare"). Nevertheless, its construction had significant symbolic value. It formalized and monumentalized the Argiletum, a once-chaotic and densely trafficked street, integrating it into the architectural order of the imperial city. The act of bringing coherence to such a space was itself a statement of imperial control and urban rationalization.

At the center of the forum was the Temple of Minerva, Domitian’s favored deity. Despite efforts to suppress Domitian’s memory, the temple remained dedicated to Minerva and was preserved by Nerva, who positioned himself as a restorer rather than a builder. Relief sculpture and inscriptions within the forum emphasized divine wisdom and civic harmony—values associated with both Minerva and Nerva’s short but stabilizing reign.

Trajanic and Later Period
Under Trajan (reigned 98–117 CE), the Forum of Nerva remained intact and continued to function as part of the broader complex of imperial fora. However, its narrow design and lack of large open spaces meant it played a lesser role in judicial or ceremonial functions. Instead, it served as an architectural connector and as part of the visual and ideological continuum linking the Flavian and earlier Julio-Claudian fora.

The Temple of Minerva remained a prominent feature, and its association with wisdom and governance allowed for ideological continuity under the new regime. Trajan’s own forum, constructed shortly after, overshadowed the Forum of Nerva in scale and function, though not in symbolic placement within the urban fabric.

Late Imperial Period and Decline
By the third and fourth centuries CE, the Forum of Nerva had largely become a fixed monument within the urban landscape, with diminished active function. The temple and porticoes continued to be maintained, but the forum no longer served as a site of political activity. It was referenced occasionally in administrative records and itineraries, indicating its continued physical presence and spatial significance.

Like other monuments of the early imperial period, the forum gradually fell into disuse as Rome’s political center shifted eastward and the city’s economic and administrative base deteriorated. The rise of Christianity and the subsequent abandonment or repurposing of pagan temples likely affected the status of the Temple of Minerva, though specific records of conversion or demolition are absent.

Post-Antique Transformation and Rediscovery
In the medieval period, much of the Forum of Nerva was buried or incorporated into newer constructions. Its decorative materials were quarried, and knowledge of its original layout and function faded. The temple itself likely survived in partial form until the early Middle Ages, after which it too was dismantled.

The site was gradually uncovered in the modern period through excavations conducted between the nineteenth and twentieth centuries. The partially preserved columns and sculptural reliefs of the colonnade were key to identifying the forum and reconstructing its historical role. Particularly notable are the reliefs depicting Minerva and scenes from Roman myth and civic life, which reflect the propagandistic aims of the original project.

Today, the Forum of Nerva is recognized not for its scale but for its urban function and its transitional ideological significance. It marked a shift from the grand public spaces of earlier emperors to a more constrained yet symbolically dense use of available space—a reflection of both physical limitations and political reorientation during the final decades of the first century CE.

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.