The original, low-lying, grassy wetland of the Forum was drained in the 7th century BC with the building of the Cloaca Maxima, a large covered sewer system that emptied into the Tiber, as more people began to settle between the two hills.
According to tradition, the Forum's beginnings are connected with the alliance between Romulus, the first king of Rome controlling the Palatine Hill, and his rival, Titus Tatius, who occupied the Capitoline Hill. An alliance formed after combat had been halted by the prayers and cries of the Sabine women. Because the valley lay between the two settlements, it was the designated place for the two peoples to meet. Since the early Forum area included pools of stagnant water, the most easily accessible area was the northern part of the valley which was designated as the Comitium. It was here at the Vulcanal that, according to the story, the two parties laid down their weapons and formed an alliance.
The Forum was outside the walls of the original Sabine fortress, which was entered through the Porta Saturni. These walls were mostly destroyed when the two hills were joined. The original Forum functioned as an open-air market abutting on the Comitium, but eventually outgrew its day-to-day shopping and marketplace role. As political speeches, civil trials, and other public affairs began to take up more and more space in the Forum, additional fora throughout the city began to emerge to expand on specific needs of the growing population. Fora for cattle, pork, vegetables and wine specialised in their niche products and the associated deities around them.
Rome's second king, Numa Pompilius (r. 715–673 BC), is said to have begun the cult of Vesta, building its house and temple as well as the Regia as the city's first royal palace. Later Tullus Hostilius (r. 673–642 BC) enclosed the Comitium around the old Etruscan temple where the senate would meet at the site of the Sabine conflict. He is said to have converted that temple into the Curia Hostilia close to where the Senate originally met in an old Etruscan hut. In 600 BC Tarquinius Priscus had the area paved for the first time.
A view of the Roman Forum seen from a window of the Palazzo Senatorio: at the centre the church of Santi Luca e Martina (beside it at the right can be seen the roof of the Curia Julia), at the lower right corner the Arch of Septimius Severus
Augustus-era coin from 37–34 BC with a representation of the Temple of Divus Iulius. Visible are the altar, a statue of Caesar veiled and with a lituus, and a star in the tympanum.
During the Republican period the Comitium continued to be the central location for all judicial and political life in the city. However, in order to create a larger gathering place, the Senate began expanding the open area between the Comitium and the Temple of Vesta by purchasing existing private homes and removing them for public use. Building projects of several consuls repaved and built onto both the Comitium and the adjacent central plaza that was becoming the Forum.
The 5th century BC witnessed the earliest Forum temples with known dates of construction: the Temple of Saturn (497 BC) and the Temple of Castor and Pollux (484 BC). The Temple of Concord was added in the following century, possibly by the soldier and statesman Marcus Furius Camillus. A long-held tradition of speaking from the elevated speakers' Rostra—originally facing north towards the Senate House to the assembled politicians and elites—put the orator's back to the people assembled in the Forum. A tribune known as Caius Licinius (consul in 361 BC) is said to have been the first to turn away from the elite towards the Forum, an act symbolically repeated two centuries later by Gaius Gracchus.
This began the tradition of locus popularis, in which even young nobles were expected to speak to the people from the Rostra. Gracchus was thus credited with (or accused of) disturbing the mos maiorum ("custom of the fathers/ancestors") in ancient Rome. When Censor in 318 BC, Gaius Maenius provided buildings in the Forum neighborhood with balconies, which were called after him maeniana, in order that the spectators might better view the games put on within the temporary wooden arenas set up there.
The Tribune benches were placed on the Forum Romanum, as well. First, they stood next to the senate house; during the late Roman Republic they were placed in front of the Basilica Porcia.
The earliest basilicas (large, aisled halls) were introduced to the Forum in 184 BC by Marcus Porcius Cato, which began the process of "monumentalizing" the site. The Basilica Fulvia was dedicated on the north side of the Forum square in 179 BC. (It was rebuilt and renamed several times, as Basilica Fulvia et Aemilia, Basilica Paulli, Basilica Aemilia). Nine years later, the Basilica Sempronia was dedicated on the south side.
Many of the traditions from the Comitium, such as the popular assemblies, funerals nobles and games, were transferred to the Forum as it developed. Especially notable was the move of the comitia tributa, then the focus of popular politics, in 145 BC. Particularly important and unprecedented political events took place in 133 BC when, in the midst of riots in and around the Forum, the Tribune Tiberius Gracchus was lynched there by a group of Senators.
In the 80s BC, during the dictatorship of Sulla, major work was done on the Forum including the raising of the plaza level by almost a meter and the laying of permanent marble paving stones. (Remarkably, this level of the paving was maintained more or less intact for over a millennium: at least until the sack of Rome by Robert Guiscard and his Normans in 1084, when neglect finally allowed debris to begin to accumulate unabated.)
In 78 BC, the immense Tabularium (Records Hall) was built at the Capitoline Hill end of the Forum by order of the consuls for that year, M. Aemilius Lepidus and Q. Lutatius Catulus. In 63 BC, Cicero delivered his famous speech denouncing the companions of the conspirator Catiline at the Forum (in the Temple of Concord, whose spacious hall was sometimes used as a meeting place by the Senators). After the verdict, they were led to their deaths at the Tullianum, the nearby dungeon which was the only known state prison of the ancient Romans.
Over time, the Comitium was lost to the ever-growing Curia and to Julius Caesar's rearrangements before his assassination in 44 BC. That year, two supremely dramatic events were witnessed by the Forum, perhaps the most famous ever to transpire there: Marc Antony's funeral oration for Caesar (immortalized in Shakespeare's famous play) was delivered from the partially completed speaker's platform known as the New Rostra and the public burning of Caesar's body occurred on a site directly across from the Rostra around which the Temple to the Deified Caesar was subsequently built by his great-nephew Octavius (Augustus). Almost two years later, Marc Antony added to the notoriety of the Rostra by publicly displaying the severed head and right hand of his enemy Cicero there.
After Julius Caesar's death, and the end of the subsequent Civil Wars, Augustus would finish his great-uncle's work, giving the Forum its final form. This included the southeastern end of the plaza where he constructed the Temple of Divus Iulius and the Arch of Augustus there (both in 29 BC). The Temple of Divius Iulius was placed between Caesar's funeral pyre and the Regia. The Temple's location and reconstruction of adjacent structures resulted in greater organization akin to the Forum of Caesar. The Forum was also witness to the assassination of a Roman Emperor in 69 AD: Galba had set out from the palace to meet rebels but was so feeble that he had to be carried in a litter. He was immediately met by a troop of his rival Otho's cavalry near the Lacus Curtius in the Forum, where he was killed.
During these early Imperial times, much economic and judicial business transferred away from the Forum to larger and more extravagant structures to the north. After the building of Trajan's Forum (110 AD), these activities transferred to the Basilica Ulpia.
The white marble Arch of Septimius Severus was added at the northwest end of the Forum close to the foot of the Capitoline Hill and adjacent to the old, vanishing Comitium. It was dedicated in 203 AD to commemorate the Parthian victories of Emperor Septimius Severus and his two sons against Pescennius Niger, and is one of the most visible landmarks there today. The arch closed the Forum's central area. Besides the Arch of Augustus, which was also constructed following a Roman victory against the Parthians, it is the only triumphal arch in the Forum. The Emperor Diocletian (r. 284–305) was the last of the great builders of Rome's city infrastructure and he did not omit the Forum from his program. By his day it had become highly cluttered with honorific memorials. He refurbished and reorganized it, building anew the Temple of Saturn, Temple of Vesta and the Curia Julis. The latter represents the best-preserved tetrarchic building in Rome. He also reconstructed the rostra at each end of the Forum and added columns.
The reign of Constantine the Great saw the completion of the construction of the Basilica of Maxentius (312 AD), the last significant expansion of the Forum complex. This restored much of the political focus to the Forum until the fall of the Western Roman Empire almost two centuries later.
The city's estimated population fell from 750,000–800,000 to 450,000 in 450 AD to 250,000 by 500 AD. The populated areas contracted to the river. Strenuous efforts were made to keep the Forum (and the Palatine structures) intact, not without some success. In the 6th century some of the old edifices within the Forum began to be transformed into Christian churches. On 1 August 608, the Column of Phocas, a Roman monumental column, was erected before the Rostra and dedicated or rededicated in honour of the Eastern Roman Emperor Phocas. This proved to be the last monumental addition made to the Forum. The emperor Constans who visited the city in 665 AD stripped the lead roofs which exposed the monumental buildings to the weather and hastened deterioration. By the 8th century the whole space was surrounded by Christian churches taking the place of the abandoned and ruined temples.
An anonymous 8th-century Einsiedeln Itinerary reports that the Forum was already falling apart at that time. During the Middle Ages, though the memory of the Forum Romanum persisted, its monuments were for the most part buried under debris, and its location was designated the "Campo Vaccino" or "cattle field," located between the Capitoline Hill and the Colosseum.
After the 8th century the structures of the Forum were dismantled, re-arranged and used to build feudal towers and castles within the local area. In the 13th century these rearranged structures were torn down and the site became a dumping ground. This, along with the debris from the dismantled medieval buildings and ancient structures, helped contribute to the rising ground level.
The return of Pope Urban V from Avignon in 1367 led to an increased interest in ancient monuments, partly for their moral lesson and partly as a quarry for new buildings being undertaken in Rome after a long lapse.
The Forum Romanum suffered some of its worst depredations during the Italian Renaissance, particularly in the decade between 1540 and 1550, when Pope Paul III exploited it intensively for material to build the new Saint Peter's Basilica. Just a few years before, in 1536, the Pope had issued an invitation to Holy Roman Emperor Charles V to hold a triumph in Rome on his return from conquering Tunis in North Africa. To prepare the Forum for the procession intended to imitate the pageantry of the ancient Roman triumph, the papal authorities undertook sweeping demolitions of the many medieval structures on the site, to reveal and better display the ancient monuments. This required the clearance of some 200 houses and several churches, the excavation of a new "Via Sacra" to pass under the arches of Titus and Septimius Severus, and the excavation of the more prominent monuments to reveal their foundations.
In 1425 Pope Martin V issued a papal bull inaugurating a campaign of civic improvement and rebuilding in the city, which was depopulated and dominated by ruins. The demand for building materials consequently increased significantly, making the forum a convenient quarry for stone and marble. Since the 12th century, when Rome's civic government was formed, responsibility for protecting the ruins of the forum fell to the maestri di strade under the authority of the Conservatori, Rome's senior magistrates. Historically, the maestri and the Conservatori saw themselves as guardians of Rome's ancient legacy and zealously protected the ruins in the forum from further destruction, but in the 15th century the Papacy gradually encroached upon these prerogatives. The Bull of 1425 strengthened the powers of the maestri in protecting the ruins, but in conferring papal authority the Vatican essentially brought the maestri under its' control and away from the independence of the Conservators.
In the 15th century, the Vatican escalated the issuance of excavation licenses, which gave broad permission to individuals to mine specific sites or structures for stone. In 1452, the ability of the maestri to issue their own excavation licenses was revoked by the Bull of Nicholas V, which absorbed that power into the Vatican. From then on only two authorities in Rome had the power to issue such licenses: the Vatican and the Conservators. This dual, overlapping authority was recognized in 1462 by a Bull of Pius II.
Within the context of these disputes over jurisdiction, ruins in the forum were increasingly exploited and stripped. In 1426, a papal license authorized the destruction of the foundations of a structure called the "Templum Canapare" for burning into lime, provided that half the stone quarried be shared with the Apostolic Camera (the Papal treasury). Between 1431-62 the huge travertine wall between the Senate House and the Forum of Caesar adjoining the Forum Romanum was demolished by grant of Eugenius IV, followed by the demolition of the Templum Sacrae Urbis (1461-2), the Temple of Venus and Rome (1450), and the House of the Vestals (1499), all by papal license. The worst destruction in the forum occurred under Paul III, who in 1540 revoked previous excavation licenses and brought the forum exclusively under the control of the Deputies of the Fabric of the new Saint Peter's Basilica, who exploited the site for stone and marble. Monuments which fell victim to dismantling and the subsequent burning of their materials for lime included the remains of the Arch of Augustus, the Temple of Caesar, parts of the Temple of Antoninus and Faustina, the Temple of Vesta, the steps and foundation of the Temple of Castor and Pollux, and the Regia. The Conservators protested vehemently against the ruination of their heritage, as they perceived it, and on one occasion applied fruitlessly to Pope Gregory XIII (1572-1585) to revoke all licenses for foraging materials, including the one granted to the fabbrica of Saint Peter's in the forum.
Excavation and preservation
The Roman Forum was a site for many artists and architects studying in Rome to sketch during the 17th through the 19th century. The focus of many of these works produced by visiting Northern artists was on current state of the Roman Forum, known locally as the "Campo Vaccino", or "cow field", due to the livestock who grazed on the largely ignored section of the city. Claude Lorrain's 1636 Campo Vaccino shows the extent to which the building in the forum were buried under sediment. From about 1740 to his death in 1772, the artist Giovanni Battista Piranesi worked on a series of 135 etchings depicting 18th-century Rome. Renowned British artist J.M.W. Turner painted Modern Rome – Campo Vaccino in 1839, following his final trip to the city.
The excavation by Carlo Fea, who began clearing the debris from the Arch of Septimius Severus in 1803 marked the beginning of clearing the Forum. Excavations were officially begun in 1898 by the Italian government under the Minister of Public Instruction, Dr. Baccelli. The 1898 restoration had three main objectives: restore fragmented pieces of columns, bases, and cornices to their original locations in the Forum, reach the lowest possible level of the Forum without damaging existing structures, and to identify already half-excavated structures, along with the senate house and Basilica Aemilia. These state-funded excavations were led by Dr. Giacomo Boni until he died in 1925, stopping briefly during World War I.
In 2008 heavy rains caused structural damage to the modern concrete covering holding the "Black Stone" marble together over the Lapis Niger in Rome. Excavations in the forum continue, with new discoveries by archeologists working in the forum since 2009 leading to questions about Rome's exact age. One of these recent discoveries includes a tufa wall near the Lapis Niger used to channel water from nearby aquifers. Around the wall, pottery remains and food scraps allowed archeologists to date the likely construction of the wall to the 8th or 9th century BC, over a century before the traditional date of Rome's founding.
In 2020, Italian archaeologists discovered a sarcophagus and a circular altar dating to the 6th century BC. Experts disagree whether it is a memorial tomb dedicated to Rome's legendary founder, Romulus.