The Forum of Caesar: The First Act

Origins and Financing

The Forum of Caesar was the first of the Imperial Fora — it predates the Forum of Augustus by seventy years and inaugurates the model that successive emperors would replicate until the second century AD. Caesar conceived the square during the campaign of Pharsalus (48 BC) and promised its construction as an ex-voto to Venus Genetrix, mythical ancestress of the gens Iulia.

The financing was extraordinary: Suetonius and Appian mention the sum of 100 million sesterces spent on land acquisition. This figure — equivalent to the annual pay of an entire legionary army — was necessary because the land lay in the densest and most expensive part of central Rome, immediately north of the Roman Forum. The Forum of Caesar was therefore, before being an act of urbanism, an act of wealth concentration: a private individual buying a piece of Rome.

The Forum was inaugurated in 46 BC alongside the celebrations of Caesar's fourfold triumph, but construction work continued after his death under Augustus, who completed it in 29 BC.

The Layout

The Forum of Caesar had an elongated rectangular form — approximately 160 × 75 metres — with colonnades on three sides. The fourth side (short, at the head) was occupied by the Temple of Venus Genetrix, which dominated the space from the height of a podium.

The double-aisled portico surrounding the square contained commercial premises and offices on the ground floor, probably with an upper storey. This model — closed rectangular square with a head temple — becomes the canon for the subsequent Imperial Fora.

The Temple of Venus Genetrix

The temple was octastyle (eight columns across) on a tall podium. It housed some of the most precious works of art in the ancient world: a cult statue of Venus (which some ancient authors describe as an idealised portrait of Cleopatra), another statue of Cleopatra in pure gold, and — according to Pliny — six collections of engraved gems (dactyliotheke). It was also the place where Alexander the Great's gilded armour was kept, which Caesar had contemplated during his visit to a temple at Ephesus.

The cult statue of Venus was a direct commission from Caesar. The goddess was represented as an armed figure: not the erotic Venus of the Hellenistic tradition but a Venus Victrix — a warrior Venus. The political message was transparent: Caesar's family descended from the goddess of war and love.

The Forum of Caesar Today

The Forum of Caesar is visible today along Via dei Fori Imperiali. Surviving structures include:

  • Three columns of the Temple of Venus Genetrix, re-erected in the nineteenth century
  • The podium of the temple
  • Foundations of the portico
  • A stretch of the Argiletum (the book-trade street that the Forum absorbed)

The three columns are among the most iconic images of the area.

The Forum of Augustus: The Response

Battlefield Vow and Construction

The Forum of Augustus was vowed before the Battle of Philippi (42 BC), when Octavian swore that if he defeated the tyrannicides (Brutus and Cassius) he would build a temple to Mars Ultor — "Mars the Avenger". Victory came, and the vow was honoured: but the Forum took forty years to complete, inaugurated at last in 2 BC.

This interval — forty years between vow and inauguration — is not negligence but strategy. Augustus waited until he had defined his title (the princeps, the "first citizen"), his iconography, and his historical narrative, before giving the city a monument that carried his programme.

The Layout

The Forum of Augustus was even more monumental than the Forum of Caesar: approximately 125 × 118 metres, nearly square. Again, a rectangular square with lateral colonnades and a head temple. The differences from the Caesarian model were nevertheless significant.

The porticoes with exedrae: the Forum of Augustus had two large semicircular exedrae on the long sides, which visually expanded the space and provided additional areas for statues and ceremonies. This invention — the portico with exedra — becomes one of the canonical elements of imperial architecture.

The rear wall: on the north side, an imposing tufa wall (the so-called murus Augustei) separated the Forum from the Subura district, one of the most densely populated and degraded areas of Rome. The wall — which still stands at nearly 30 metres — also served as a firebreak: the Subura burned frequently, and the Augustan Forum was not to burn with it.

The use of statues: the porticoes were conceived as a gallery of ancestors — statues of the summi viri of Roman history, from Aeneas to Romulus to the great generals of the Republic. At the centre of each exedra: an equestrian colossus of Augustus. The message: all the great Romans of history have led to this moment.

The Temple of Mars Ultor

The temple was octastyle on a very tall podium (approximately 3.5 metres). Three Corinthian columns of the upper order are still standing — they are among the finest capitals in the Roman world. The interior housed cult statues of Mars and Venus (recalling the double divine ancestry of the gens Iulia), plus a sword said to have been Julius Caesar's.

The Temple of Mars Ultor had a precise ceremonial function: it was the place where Roman generals went before departing on military campaigns, and where they deposited the spoils of victory on their return. The Senate met here to deliberate on war and peace. It was, in short, the heart of imperial military policy.

Augustus's Programme: Propaganda and Architecture

The Forum of Augustus was a political programme translated into stone. Every element had an ideological function:

The statues of the summi viri: the gallery of Roman heroes was arranged chronologically, culminating with Augustus. The message: Roman history is an unbroken chain leading to me.

Aeneas and Romulus in the exedrae: in the left exedra, the Julian descent from Aeneas (with his father Anchises and his son Ascanius/Iulus); in the right exedra, the kings of Rome from Romulus. Two roots of the gens Iulia and of Rome itself.

The dedication of 2 BC: the Forum was inaugurated in the year the Senate conferred on Augustus the title of pater patriae — father of the fatherland. The coincidence was not accidental.

The Forums of Caesar and Augustus in Urban Context

The Roman Forum was the space of the res publica: it belonged to the community, had been built over centuries by magistrates and governors, and no single person had ever stamped their own name on it so explicitly. The Forums of Caesar and Augustus broke this tradition: they were private forums made public, forums bearing the name of the patron.

The urban effect was twofold: on one hand, the civic centre of Rome multiplied (the Imperial Fora would continue to expand with Vespasian, Nerva, and Trajan); on the other, the message was clear: Rome was no longer the res publica of the Romans but the res of a family.

How to Visit the Forums of Caesar and Augustus

The Imperial Fora, including the Forums of Caesar and Augustus, are visible from outside along Via dei Fori Imperiali (free access to the external walkway). Internal access is part of the Roman Forum area.

The Forum of Caesar: the three columns are visible from Via dei Fori Imperiali. The structure is partly excavated below the level of the modern road.

The Forum of Augustus: the head wall with three Corinthian columns and part of the Temple of Mars podium are the most visible remains. The Museum of the Imperial Fora (in Trajan's Market) complements the visit with reconstructive models and materials.

Visit the Forums of Caesar and Augustus with a Private Driver

The Imperial Fora lie at the heart of Rome, along Via dei Fori Imperiali.

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Frequently Asked Questions

When was the Forum of Caesar built? The Forum of Caesar was vowed in 48 BC during the Pharsalus campaign and inaugurated in 46 BC with Caesar's fourfold triumph. Completion work continued under Augustus, who finished it in 29 BC.

What was kept in the Temple of Venus Genetrix? The temple housed the cult statue of Venus, a golden statue of Cleopatra, Alexander the Great's gilded armour, and six gem collections. It was also the symbolic seat of Caesar's divine ancestry.

Why did Augustus build a forum dedicated to Mars? The Forum of Augustus was vowed before the Battle of Philippi (42 BC) as a promise to Mars if Octavian defeated Caesar's murderers Brutus and Cassius. The Temple of Mars Ultor ("Mars the Avenger") commemorated this victory.

Can you visit the Forums of Caesar and Augustus? The Fora are visible from outside along Via dei Fori Imperiali for free. Internal access is part of the Roman Forum area (combined ticket). The Museum of the Imperial Fora in Trajan's Market offers the most complete view with 3D reconstructions.

How many Imperial Fora are there in total? Five principal Imperial Fora: Forum of Caesar, Forum of Augustus, Templum Pacis (Vespasian), Forum of Nerva (or Transitorium), Forum of Trajan. The last is the largest and best preserved.

Article no. 54 — TIER S — MON-03 Roman Forum + Palatine Type: HISTORY Words: ~2,400

See also