The forum included several important buildings such as the Temple of Mars the Avenger (Tempio di Marte Ultore) and the Temple of Jupiter Tonans (Tempio di Giove Tonante). It also served as a location for important political and religious events and was decorated with statues and other works of art. The forum was a major center of Roman life for several centuries, but fell into disuse and ruin after the fall of the Western Roman Empire in the fifth century CE.

circa 2 BCE

Late Republican Period
The origins of the Forum of Augustus are rooted in the political and ideological aftermath of the late Roman Republic. Following the assassination of Julius Caesar in 44 BCE and the ensuing civil wars, Octavian—later emperor Augustus—emerged as the dominant political figure. It was during this transitional phase, particularly after his victory at the Battle of Philippi in 42 BCE over the assassins of Caesar, that Augustus vowed to build a temple to Mars Ultor (Mars the Avenger). The promise was deeply symbolic, intended to associate his regime with divine vengeance and filial piety, thus legitimizing his position as Caesar’s heir and Rome’s restorer. Although the vow was made early, the actual construction of the forum would span several decades, highlighting the complexities of urban planning in an already densely populated capital.

Augustan Period
The Forum of Augustus was formally inaugurated in 2 BCE, although parts of it may still have been under construction at the time. It was conceived as both a religious and political space, complementing the earlier Forum of Julius Caesar and reinforcing the architectural dominance of the new principate. At the heart of the forum stood the Temple of Mars Ultor, a richly decorated structure that served as a cultic and ceremonial center. Flanked by exedrae containing statues of Roman heroes and ancestors—especially those of the Julian line—the forum functioned as a visual narrative of Roman virtue and imperial continuity. Augustus used the forum for senatorial deliberations, judicial proceedings, and military affairs, particularly declarations of war and treaty negotiations, thereby linking his authority to the martial traditions of early Rome.

The architectural layout emphasized symmetry and monumentality, employing Luna marble and Corinthian columns in a distinctly Augustan aesthetic. The iconographic program was tightly controlled to reflect Augustus’s political messaging, emphasizing pietas, virtus, and the restoration of Roman order after decades of civil conflict. The sculptural decoration included Aeneas, Romulus, and other legendary figures, drawing a direct line from mythic founders to the Julian dynasty. The forum’s integration into the wider urban landscape also demonstrated the Augustan commitment to reshaping the capital as a visual embodiment of imperial ideology.

Julio-Claudian and Flavian Periods
Following the death of Augustus in 14 CE, the Forum of Augustus continued to function as an active civic and ceremonial space under his successors. Tiberius, Caligula, and Claudius made minor additions or restorations, although the core structure and program remained intact. Under the Flavian emperors, particularly Vespasian and Domitian, the forum retained its symbolic significance as a legitimizing monument for new dynasties. Domitian is known to have undertaken restoration work and possibly reinforced the ideological continuity between the Julian and Flavian lines through renewed attention to the forum’s statuary and inscriptions.

Despite these interventions, no major structural overhauls were implemented, which indicates the sacral and political inviolability of the Augustan design. The forum became a site not only for memory politics but also for reaffirming imperial orthodoxy through architecture. Its use in triumphal celebrations and its association with Mars Ultor further linked military success with divine favor, a theme later replicated in the adjacent Forum of Trajan.

Middle Empire Period
During the second century CE, particularly under Trajan and Hadrian, the Forum of Augustus was increasingly overshadowed by newer architectural projects. Nonetheless, it retained its prestige and remained part of the ceremonial and ideological geography of imperial Rome. The adjacent construction of the Forum of Trajan did not diminish the forum’s symbolic import but rather created a continuum of imperial fora, each reinforcing the legitimacy and grandeur of Rome’s emperors through monumental urbanism.

Hadrian’s known interest in Augustan ideals and his architectural conservatism likely contributed to maintenance efforts, although specific records are sparse. The function of the forum evolved gradually, with less emphasis on its judicial and senatorial functions and more on its commemorative and religious roles. Statues and honorific inscriptions continued to be added or restored, maintaining the forum’s relevance in the imperial cult and in the spatial politics of Roman memory.

Late Empire and Decline
By the third century CE, the Forum of Augustus, like many structures in the imperial capital, experienced gradual neglect amid the empire’s political fragmentation and economic stress. While some emperors of the later Severan dynasty may have attempted partial restorations, the lack of cohesive urban policy and increasing threats from both internal and external pressures led to the forum’s decline as a functional civic space.

During the fourth and fifth centuries CE, the Christianization of Rome and shifting imperial priorities led to a further marginalization of pagan monumental complexes. The Temple of Mars Ultor, like many other temples, likely fell into disuse or was repurposed. By the sixth century, spoliation of architectural materials became common, with marble and decorative elements reused in Christian buildings or public works.

Post-Classical and Archaeological Recovery
The Forum of Augustus remained buried and largely forgotten for centuries, its memory preserved only through scattered references in late antique texts and Renaissance antiquarianism. Serious archaeological investigation began in the late nineteenth and early twentieth centuries, culminating in major excavations during the Fascist period under Mussolini. These efforts aimed not only at historical recovery but also at ideological appropriation, as the forum was presented as a symbol of Roman greatness and imperial legacy.

Modern scholarship has since disentangled the layers of use, reuse, and reinterpretation that the site underwent. Today, the Forum of Augustus stands as a crucial case study in the interplay between architecture, ideology, and memory in the Roman world. Its layout, iconography, and evolving function provide vital insight into the construction of imperial identity and the uses of urban space in antiquity.

circa 2 BCE

Temple of Mars Ultor
The Temple of Mars Ultor (literally meaning the Mars the Avenger) occupied the centre of the eastern side of the Forum of Augustus. It was dedicated by Octavian Augustus in 42 BCE on the eve of the battle of Phillippi fought together with Mark Antony against Brutus and Cassius to avenge the assissination of Julius Caesar, his uncle and adopting father. The temple (illustration) was inaugurated in the year 2 BCE. Ancient reliefs display the fronton which bore in the center the statues of Mars and Venus as the ancestors of the Romans and the Julia family, to which both Julius Caesar and Octavian belonged. To the sides of the divine couple there were personifications of Fortune, Rome Palatine, the Tiber and the image of Romulus, the mythical founder of Rome in 753 BCE and its first king. The significance of this group lies in the legitimization of power of the Julia family who, according to the legend, descended from Julus Ascanius, son of Aeneas, son of Venus. From Julus Ascanius descended also Reha Silvia, who had conceived Romulus with Mars. The temple was completely destroyed around the times of the Ostrogoth king Theodoric (circa 493-526 CE) in order to reuse the marble and other construction materials. They were spared only the three columns still standing and the podium. In the ninth or tenth century CE, the very first nucleus of the monastery of Saint Basil was settled. Between the end of the twelfth and the beginning of the thirteenth century CE, the monastery became the property of the Knights of Saint John of Jerusalem (later called the Knights of Rhodes, today known as the Knights of Malta). In 1566 CE the complex was donated by Pope Pius V (1566-1572 CE) to a group of Dominican nuns, who built a new monastery and a new church, which occupied the area of the Temple of Mars and was dedicated to the Virgin of the Annunciation. Most of these structures has been demolished in1924-1932 CE to recover the Roman ruins. Many fragments of sulptures found at the time are on display at the Museum of the Imperial Fora.

circa 2 BCE

The Square of the Augustan Forum
The excavations carried out between 2004 and 2006 CE by the Superintendency of Cultural Heritage for the City of Rome brought to light the part of the central area of the Forum of Augustus, stretching for approximately five hundred square meters. The square was originally paved with Carrara marble (from Tuscany) and was likely decorated with severalstatues. The analysis of the rich archaeological data showedthat the marble paving of the Forum had long been removed and the area had been abandoned, with subsequent natural soil accumulation, between the ninth and tenth centuries CE. The construction of the nearby monastery Saint Basil, built at the time on the podium of the Temple of Mars Ultor, could explain the removal of marble and other materials from the square of the FOrum, in order to obtain building materials. For many centuries the area was unkempt and marshy, until it was drained in the second half of the sixteenth century CE. Finally, starting from the year 1584 CE, the first buildings of the Quartiere Alessandrine were built in the area. The structures were built right on top of the Forum of Augustus, unfortunately causing the complete removal of what remained of the decorative elements dating back to the Roman period.

circa 2 BCE

The Side Porticos and Hemicycles
On the two long sides the square of the Forum of Augustus was flanked by porticoes. The facade was decorated with fluted Corinthian columns made of Giallo Antico marble (coming from the modern day Tunisia). The columns supported an attic decorated with Caryatids modeled on those from the Erechtheum in Athens and alternating with large marble shields bearing heads of deities in the center. The porticoes floors displayed rich coloured marble patterns and each of them opened up to a pair of hemicycles with a diameter of fourty meter. The western pair of the hemicycles were demolished during the construction of the Forum of Nerve circa 97 CE and the Forum of Trajan circa 112-113 CE so that the porticoes in the Forum of Augustus were left with only one hemicycle each.

These spaces were furnished with a gallery of statues portraying famous men of Rome (Summi Viri) as well as members of the Julia dynasty to which Augustus himself belonged. Trials would be held inside the hemicycles by the ancient Roman judges (praetores). In the northern hemicycle the praetor urbanus would preside over law-suits involving Roman citizens while in the opposite hemicycle (south) the praetor peregrinus would attent to the legal matters involving foreigners (peregrini) who did not have the Roman citizenship. The northern portico endedin a lavishly decorated room, the so-called "Hall of the Colossus" (in front of you). A colossal statue of Augustus (approximately eleven or twelve meters tall) was placed on a base in this hall as a symbol of the equality of justice administered by the judges in the nearby tribunals. Several marble fragments coming from this section of the Forum of Augustus are on display in the Museum of the Imperial Fora.