Introduction to the Arch of Constantine

By: TammyJo Eckhart, PhD on 9/30/2019


Rome Reborn® apps present the buildings of the Eternal City at a moment in time, 320 CE, when Constantine was emperor. We get to see buildings that had been in use for centuries and ones that were relatively brand new at the time the apps are set. Today let me introduce you to the Arch of Constantine, the biggest surviving triumphal arch in Rome which you will find in our Colosseum District app.

The arch was dedicated on July 25, 315, three years after Constantine’s victory at the Milvian Bridge. It is situated in the Colosseum Valley between the Caelian and Palatine hills. The most impressive structure in the area was the Flavian Amphitheater or Colosseum. While the amphitheater was used only on special occasions, people still generally frequented the area, which was adjacent to one of the city’s major roads, the Sacred Way. They might also be in the neighborhood to watch gladiatorial training in a nearby facility, shop at numerous businesses, and visit other nearby monuments. So, for a variety of practical reasons the choice to put the Arch of Constantine here is not surprising: a lot of people would see regularly it.

Moreover, like many other triumphal monuments in Rome, it sits along the route of the triumphal parade and so is also in a symbolically laden location. Indeed, the arch’s inscription makes it clear that it served as a reminder of his victory and right to rule alone. In English the inscription, identical on both sides, reads:

    To the emperor Flavius Constantine, the Great,

    Pious and fortunate, the Senate and People of Rome,

    Because by divine inspiration and his own greatness of spirit

    With his army

    On both the tyrant and all his

    Faction at once in rightful

    Battle he avenged the State,

    Dedicated this arch as a mark of triumph.


The unnamed “tyrant” refers to Maxentius, whom Constantine defeated. The “divine inspiration” and “spirit” makes no mention of the cross, a symbol Constantine claimed he saw in a dream and used in battle to gain victory. The arch was dedicated by the Senate, still an overwhelmingly pagan institution, which may explain why the cross, with its Christian associations, was left out.

The size of the arch is similar to that of Septimius Severus in the Roman Forum: the central arch was large enough for a triumphal party to parade through and was flanked by two smaller archways. Examination of the materials that decorate the arch has revealed that it was made from spolia, reclaimed marble and sequential art sections from other structures. It was common to reuse materials from earlier buildings and monuments starting in late antiquity, and it is sometimes claimed that such recycling suggests that Rome itself was on the decline. Be that as it may, Constantine was soon to move the capital of the empire from Rome to his new headquarters in the east, Constantinople, and there is no evidence that he ever returned to Rome to see the arch dedicated to him.

Rome Reborn®’s Colosseum District app will give you a detailed look at each section of the Arch of Constantine so let this essay just give you an idea of what you will encounter. The app’s virtual reconstruction paired with the voiceover will help you to understand the complexities of the monument much better than the mere words of this essay could.

While the bulk of the arch was a grayish white marble, color was used to highlight certain features and decorations. For example, the front and back of the arch had four “giallo antico” (i.e, yellow) shafts on the fluted Corinthian columns (though one was replaced by a pavonazzetto [i.e., purplish] shaft by Pope Clement VIII around 1597). Other examples of color on the Arch of Constantine were the purple-red porphyry around the rondels, and the cipollino (i.e., greenish marble) on the pedestal bases carrying the Dacian prisoner statues.

In addition to the Dacians, friezes are a prominent feature of the arch’s décor, far exceeding in number and import what we find on such other surviving triumphal arches at Rome such as the Arch of Septimius Severus and the Arch of Titus. In the Rome Reborn® app, you can see the restoration of color to the reliefs following precedents known from the few works of Roman official art whose color scheme is well enough preserved to be studied. The so-called “Great Trajanic Frieze” consists of two sections, or four panels, and is on the inside of the main archway and on the top of the two short sides. The images on the frieze also look a lot like those on Domitian’s surviving monuments, so calling these “Trajanic” is more label than absolute proven fact. The head of the victorious emperor in this frieze as well as the others shows signs of being recut to resemble Constantine.

Despite all the recycling of older decorative elements, new friezes were also created specifically for the Arch of Constantine. These begin on the short west side of the arch and continue around the entire structure in the areas immediately above and around the archways. The newly created frieze told the story of Constantine defeating Maxentius from the start of his march from Milan through his triumphal celebration in Rome.

There are ten roundels on the Arch of Constantine. Eight “Hadrianic roundels” are set in pairs on the front and back of the arch. These rondels again show signs of being recut to resemble Constantine and perhaps his father Constantius Chlorus as leaders participating in hunts and sacrifices. The other two roundels are on the east and west sides of the arch and represent the sun and moon, respectively.

Framing the inscription are rectangular reliefs, commonly referred to as the “panel-reliefs of Marcus Aurelius,” which are placed in pairs on the sides of the inscription on both sides of the arch. While scholars agree that these were originally part of a monument dedicated to Marcus Aurelius, they do not know which one and where it was located.

While much of the original reliefs were used, there are signs that some individuals and features were recut to make them more appropriate for Constantine’s life. The south side shows military activity, while northern reliefs show civic duties, reflecting the reality of any emperor’s life. Interestingly, even though scholars argue about when Constantine became Christian, the decorations are all traditionally Roman, with various gods and goddesses.

Today you can go to Rome itself to see the Arch of Constantine. You can also find photos online to see what it looks like close up. But only in the Rome Reborn® app can you walk around it and look at what it may have been like in 320.

Finally, readers of this essay are urged not to overlook the amazing (and free) educational app posted on the Rome Reborn website. It was authored by the talented Indiana University college senior, Gretchen Creekbaum. She has created similar apps for the Museum of London. Her app on the Arch of Constantine can be found here: Keep your eye on Gretchen: she’s destined for great things!

To learn more about the emperor Constantine, read my previous essay on him.

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