This comes from my own published work called "The Once and Future Forum: Approaching Virtual Reconstructions as an Archaeological Tool" (None of the 6 pictures have been added)

In 29 BC, a monumental arch was voted on by the Roman Senate to commemorate the victory at Actium by Octavius. It was built as a one-bay arch, possibly on the south side of the Temple of the Deified Julius Caesar and, if Kleiner was correct, was removed later most likely to place the Parthian Arch of Augustus near the same place in 19 BC. Its replacement was a more elaborate triple-passageway arch commemorating the return of the standards the Parthian Empire had captured from Crassus at the Battle of Carrhae in 53 BC.

Coarelli argues that the Actian Arch was never torn down for the new Parthian Arch and that the Parthian Arch was built on the right side of the Temple of the Deified Julius. His review is questionable since two decades after the arch’s construction, the Portico of Gaius and Lucius Caesar was built and attached to the Basilica Aemilia spanning much of the way to the Temple of the Deified Julius Caesar. This leads one to conclude that Coarelli's Parthian triple arch stood in an area with insufficient space for such an important monument. One can also accept Pirro Ligorio’s accounts and drawings as archaeologically accurate though most scholars have discredited them since there are no sources for his work. The Basilica Aemilia would have concealed the arch’s passageways and attic statuary of Coarelli's Parthian gateway would have been concealed from the Forum. More acceptable is Fred Kleiner’s statement that it is unlikely that Octavius, now the Emperor Augustus, would have removed his glorious arch representing himself as a Parthian victor to instead praise his nephews.

Elisabeth Nedergaard says that two piers found by Mongenet’s Parthian arch do not necessarily represent the Actian arch and she is suspicious that Augustus would have torn down his first arch to build the second. Though the location of the Actian arch is a mystery, Cassius Dio reported from the Third Century AD that the Senate granted Augustus an arch both in Brundisium and the Roman Forum. Augustus also celebrated an ovatio for recovering Cassius’ standards and was honored with a triumphal arch. Indeed, we find in one version of Virgil’s Aeneid declaring that the Augustan arch stood iuxta aedem divi Iulii, but this neither clarifies which arch the scholiast had noted nor on what side of the temple it stood. Some clues are given thanks to cinquecento literature and recent excavations.

In 1546/7, an inscription was discovered on a block of Parian marble 2.67 m. long on the left side of the Temple of the Deified Julius Caesar. The inscription was dedicated to Augustus in 29 BC. This may have belonged to the arch proper, but it was probably not inscribed on the attic.

In 1888, O. Richter discovered the foundations of a triple arch south of the Temple of the Deified Julius Caesar, and as the one version of the Aeneid noted, its outer pier hugged the wall of the temple providing an ‘iuxta’ look. What may have been the Arch of Actium was finally uncovered in the 1950-1953 excavation by R. Gamberini Mongenet. He found two foundation blocks of the side piers in opus caementicium lying east of the triple arch (see figure 5.1). There, an inscription cut on a block of Parian marble, about 3 m. long, which was found close to these foundations, records a dedication to Augustus in 29 BC. It proves that the single arch needed to be removed to build the Parthian arch.

R. Gamberini Mongenet’s reconstructed sketch used architectural fragments within the vicinity and corresponding with Augustan coins (see figure 5.2). In it he shows a triple arch of an atypical type: a towering central arch with an inscribed attic crowned by a quadringa flanked with lower post-and-lintel fornices to each side that are born on columns and capped by triangular gables peaked with figures of barbarians offering standards to the triumphator.

If the architectural fragments attributed to this arch are rightly given, it was richly decorated, the Corinthian capitals having the echinus fixed with an egg molding, and the modillions regarded as massed guttae. The octagonal base upon which the columns is in three tiers of tufa concrete, bearing evidence of refacetting and with a marble concrete coating. Jordan states that each tier’s height from lowest to highest was 24 cm., 44 cm., and 48 cm.

The foundations consisted of travertine blocks on concrete beds, and three of the four piers are clearly in situ. The central piers were 2.95 m. wide and the outer piers were 1.35 m. The width of the center archway was 4.05 m. and the smaller fornices are 2.55 m. giving the breadth of the entire arch as 17.75 m. The pavement in the central archway is still partially preserved. When Tiberius rebuilt the Temple of Castor, the southern part of the arch was largely hidden by the temple’s steps, which were very close to it.

The reveals of the arch were adorned with the Fasti Capitolini Consulares listing all the chief magistrates since the Republic’s foundation and the Triumphales naming all triumphators from Romulus onward. Scholars formerly believed that both were on the Regia. This memorial acted as an internal urban doorway marking the entry into the central forum placed between the Temples of the Deified Julius Caesar and Castor and Pollux.

Both arches are believed to have been depicted on Roman coinage - the Actian Arch on denarii of 29/27 BC and the Parthian Arch on Spanish aurei and denarii of 18/17 BC as well as a denarius of 16 BC minted by L. Vinicius, together with a representation of a triple arch (see figure 5.3).

By 2002, the Cultural VR Lab at UCLA had built much of the Roman Forum as they understood it to look by 400 AD. One of their models was the Arch of Augustus. The model was made with Studio Max and excellently rendered, but there are problems that arise when the viewer examines the final project (see figure 5.4). Looking at a few facts known about the Arch of Augustus, the CVRLab fails to provide a quadringa at the top of the attic, a plaque at the center, and a statue of a barbarian at each side of the smaller fornices. They provide an attic above each fornix and eliminate the pedestal on which each barbarian statue stood. Metopes are not enlisted, nor are the winged victories. Corinthian and Doric fragments show that the Arch of Augustus had fluted columns, not the smooth ones that the CVRLab’s Arch of Augustus offers. Though their work gives a fine representation of how the arch may have looked, the separation of the arch from its surroundings can also give the viewer a misunderstood interpretation on the arch’s cultural significance. The neighboring buildings such as the Temple of the Deified Julius Caesar and Temple of Castor help define Roman space and the elimination of the floor’s elevation also detracts from the model’s value. A person entering the Roman Forum from the arch would see that the path slopes down from the Roman Forum by a few meters. There would also be recognition that the arch hugged the base of the Temple of the Deified Julius Caesar. There was little space within the area which gives the viewer the understanding that the arch possibly needed to be built up instead of out, hence the reason for the tall attic.

Using Parallelgraphics’ Internet Space Builder, the author was able to build the Arch of Augustus with a lower cost and less manpower (see figure 5.5). R. Gamberini Mongenet‘s sketching was used carefully in a point-by-point measurement but there were occasional oversights. The sketching shows metopes and dentals while the model carries none of these above the smaller fornices (see figure 5.6). It is important that the author added the victory relief above the central fornix and that the author shows it in scale and proportion to the other buildings. Though the provided statues are rudimentary and posed incorrectly, they help the viewer understand that there originally were figures above the fornices. The CVRLab and the author have both aided the understanding of the Arch of Augustus, yet they have equally made mistakes. The viewer can mistake either one as absolute truths about the Arch of Augustus. As many mothers say: two wrongs do not make a right.

Fred S. Kleiner, "The study of Roman triumphal and honorary arches 50 years after Kahler," Journal of Roman Archaeology, Vol. 2 (1989) (Ann Arbor, MI: Cushing-Malloy Inc., 1989), 195. Abbreviated in the future as ‘Kleiner‘.

Dio Cassius, 51. 19; 54. 8.3

Kleiner, 200, 206.

Elisabeth Nedergaard, “Zur Problematik der Augustusbogen Auf Dem Forum Romanum,” Kaiser Augustus und die Verlorene Republik (Mainz, von Zabern, 1988), 224-39; Dio Cassius, 51.19.

Ibid., 54.8.

Virgil, Aeneid. Schol. Veron. vii. 605-6. This is also mentioned in Samuel Ball Platner, Topographical Dictionary of Ancient Rome, Rev. Thomas Ashby. (London: Oxford UP, 1929), 34.

CIL, vi. 873.

Giuseppe Lugli, I Monumenti Antichi Antichi di Roma e Suburbia, Vol. 1 (Roma: Libreria di Scienze e Lettere), 140. Abbreviated in the future as ‘Lugli’.

Nash, Vol. 1, 92

CIL, vi. 873.

Nash, Vol. 1, 92-101

Baddeley, 46.

Henri Jordan, Topographie der Stadt Rom im Altertum (Berlin, Weidmannsche buchhandlung, 1871-1907), Vol. 1, 409

Diane Favro, The Urban Image of Augustan Rome (NYC: Cambridge U P, 1996), 159, 243.

Kleiner, 196.

Samuel Ball Platner, Topographical Dictionary of Ancient Rome, Rev. Thomas Ashby. (London: Oxford UP, 1929), 34.