Constantine is the central figure in the transformation of the entire Roman Empire from pagan to Christian in the fourth century, but why he initiated this dramatic change is still disputed both by historians and in the art that remembers him. Today we examine the Arch of Constantine to see what it might be able to tell us about the mystery man it honors.

Show Notes

Arch of Constantine as seen from the Colosseum (Blake Photo)

In this episode we visit the Arch of Constantine, which is one of three remaining triumphal arches in or near the Roman Forum. It was built in the name of the Senate and People of Rome to honor Constantine’s victory over the then-ruling Emperor, a certain Maxentius, whom Constantine defeated at the Battle of the Milvian Bridge just a little north of Rome’s Piazza del Popolo, on October 28, 312. It is unusual in that it honors an emperor not for conquering a foreign people but for conquering Rome itself.

Crossing the Tiber, the Milvian Bridge is just north of Piazza del Popolo

Two weeks ago, in Episode 19, we noted that Bernini also honored Constantine by placing a dramatic equestrian statue of him in the Portico of St. Peter’s Basilica, but if Bernini and the ancient Romans are similar in honoring Constantine, we will see today that they do so in very different ways and for very different reasons. But before exploring these differences, we must get to know the man a little better. This will also help us later, when we visit the Room of Constantine in the Vatican Museums, designed mostly by Raphael and painted in fresco by his students.

Bernini’s Statue of Constantine in the Portico of St. Peter’s (Vatican Photo)

Constantine’s political and military career began around the beginning of the fourth century. The Roman Empire was at this time a house sharply divided, and Constantine’s main military achievement was to put it together again, by force, for he fought his way from Britain to the Black Sea, defeated everyone who stood in his way, and made himself the sole ruler of the entire Roman Empire, which stretched from Wales to Egypt, and from North Africa to what is Bulgaria today. So Constantine’s first claim to fame is that he was a great conqueror.

The circumstances of Constantine’s rise were not promising. The Roman Empire had suffered greatly through much of the third century, especially through a series of coups in which men murdered their way to supreme authority and then were murdered in turn to remove them from it. In a period of sixty years, there had been thirty-three emperors, thirty of whom were assassinated. In light of this grave problem, after securing his own position, the Emperor Diocletian divided the Empire first into half, east and west, and then he divided each half. Under this “Tetrarchy,” which simply means “the rule of four,” the two most important parts were to be ruled by Emperors called Augusti, and the other two by Emperors called Caesars. When one of the Augusti died, he was supposed to be replaced by a Caesar, and the Caesars were to be chosen on the basis of merit, not birth. This nice and neat system would end the use of armies to seize the Imperial Purple, or so it was hoped.

The Roman Empire neatly divided into four, the Tetrarchy

The two men who would do battle in 312 at the Milvian Bridge in Rome, Constantine and Maxentius, both had fathers who had been Augusti in Diocletian’s system: Maxentius’s father retired from power, and Constantine’s father died in 306. Neither son was automatically entitled to fill in for his father, but Constantine’s army in Britain helped him to become Caesar, and then Maxentius was likewise vaulted to political power by an army in Rome. The Caesar who was supposed to have been promoted to Augustus was still hanging around, but he was too weak to rule. Diocletian’s hopes for his tetrarchy and an orderly succession of power had broken down, and the question of the rightful ruler would be settled by military force, as was confirmed by the two decades of civil wars that followed the death of Constantine’s father. Constantine was the last man standing, and he stood at the head of a large army and empire, far and away the most powerful man in the world.

Constantine’s first wars were to secure his power in Gaul and the other western parts of the Roman Empire. Then he marched on Rome and defeated Maxentius at the Milvian Bridge. Having thus secured the West, he made peace with the East, which was then ruled by Licinius, an Augustus. To seal the deal, Licinius married Constantine’s sister, and the two Augusti issued the so-called Edict of Milan, which called for religious toleration, Christianity included. This was 313.

Constantine’s Battles from West to East (306-324)

Civil war soon erupted between the two Augusti and brothers-in-law, and it continued for a decade, with Constantine winning a series of battles that allowed his share of the empire continued to expand to the East. Tension and truces marked the periods between the battles.

The end came in 324, when Constantine won two land battles, and his son Crispus added a naval battle, with each battle occurring further to the east. The coup de grâce came on September 18 at the Battle of Chrysopolis, just east of Byzantium, today’s Istanbul. The consequence was that Constantine now at the head of the entire Empire, and he then ruled it for another thirteen years, which gave him time to make some dramatic changes.

A summary indication of the violence of it all is that Constantine’s route to power required him to defeat and kill three different emperors, of whom one was his father-in-law and two were brothers-in-law. He was also was responsible for the murder of his first wife, Fausta, and his first born son, Crispus, though his reasons are not known.

Let us now return to the Roman Arch that honors Constantine near the Forum and the Colosseum. It is one of the iconic sites of Rome, and its size, rich sculpture, and monumental symmetry have inspired imitation around the globe, such as the Arc de Triomphe in Paris and the entrance to Union Station in Washington, DC. Botticelli and Perugino both painted it prominently in their beautiful frescos on the side walls of the Sistine Chapel. Its importance is further magnified by being one of only three triumphal arches that survive near the Roman Forum, an area that used to have more than thirty. But what is most intriguing about this arch is the question of its meaning.

South facade of the Arch of Constantine (Charlie’s photo)

The arch was dedicated three years after Constantine’s victory at the Battle of the Milvian Bridge, and its purpose was to honor him both for his victory and for the tenth anniversary of his rule. Twelve hundred years later, Raphael’s “Room of Constantine” in the Vatican would present this battle as part of a religious war, with his troops fighting under the sign of the cross against the pagans of Maxentius. The arch, by contrast, makes no reference to Christianity. It has no cross in the sky—no cross at all—and it even shows the emperor sacrificing to pagan deities and

accompanied by the goddess Victory. Whereas Raphael will show Constantine on his knees before Pope Sylvester, the arch includes pagan priests but no popes, and Constantine kneels to no one.

Constantine’s Vision of the Cross in the Vatican Museums by the School of Raphael (Vatican Museums Photo)

The arch has three bays or passageways and is the largest surviving Roman triumphal arch, being about 25 meters wide and almost as tall, and its general design is comparable to the Arch of Septimus Severus, which had been built a little more than a century earlier and still stands in the Forum. The arch serves as a platform for over twenty-five sculptures and carved reliefs, most of which represent scenes with multiple figures. These are divisible into two main groups. One includes the reliefs carved specifically for this arch around 315, three years after Constantine took Rome. The other group is made up of reliefs lifted from preexisting monuments. Such reused art is called “spolia” or “spoils.” The spolia are mostly taken from monuments dedicated to either Hadrian, Marcus Aurelius, or Trajan and are thus roughly a century and a half older than the reliefs from Constantine’s day. Eight circular reliefs (called tondi or rondels) at the middle level of the façades were carved during the reign of Hadrian; eight top or “attic” panels on the two main façades were taken from a monument erected in the time of Marcus Aurelius; and reliefs from the time of Trajan are on the short ends of the arch at the attic level, with two more such panels lower down on the inside of the central passageway. Other spolia include the statues of Dacian prisoners and the four large columns in front of each of the two main façades.

Arch of Septimus Severus in the Roman Forum about a century before Constantine (student photo)

The spolia steal the show, both in size and quality. The eight tondi are over six feet high; the attic and Traianic panels are about nine feet high; and the eight columns surmounted by the Dacian prisoners are the first feature we notice after the general shape of the arch. By contrast, the reliefs devoted to Constantine’s victories and civic actions are less than four feet high and cover a small fraction of the arch’s total surface area. Rather than being the focal point of the arch, they seem to have been allotted only such space as was left after the spolia were put into position. And most critics, though of course not all, are impressed by the superior quality of the older carvings; those from Constantine’s day seem cramped and lacking in all proportion.

Chart showing the location of the spolia on the Arch of Constantine

The main subjects of all the sculptures on the arch show a marked contrast with the theme stressed by Bernini’s equestrian statue and in Raphael’s “Room of Constantine” in the Vatican. Instead of witnessing a cross in the sky before the great victory celebrated by the arch, the emperor sacrifices in four of the tondi to the pagan gods Sylvanus, Diana, Apollo, and Hercules; in the other four he departs for a hunt and successfully kills a bear, a boar, and a lion. In the attic reliefs, he carries out military and civic duties, such as addressing his troops before battle, offering the sacrifice of a pig, sheep, and bull, and receiving the submission of the defeated. The reliefs from the time of Trajan show scenes pertinent to Trajan’s defeat of the Dacians, which thus are reminiscent of the Column of Trajan on the other side of the Forum.

The upper right side of the south facade of the Arch, showing (Blake Photo)

To keep Constantine from being completely overshadowed by the art and achievements of his second-century predecessors, the heads of the latter were re-sculpted or replaced so they then represented Constantine and his allies! But no changes were made to introduce crosses or angels into the scenes, and none of the pagan gods or sacrifices were Christianized in any way. The spolia on the monument contain not the slightest hint that Constantine had fought for the Christian God or had won because of His support.  To the contrary!

A closer look at the upper left side of the Arch’s south facade (Blake’s Photo)

The narrow band of six rectangular reliefs that were made specifically for this arch are squeezed into spaces just below the tondi and just above the top of the two side passageways through the arch. There are two panels on each of the two main façades, and one on each of two shorter sides. They show several stages of Constantine’s campaign against Maxentius and his entry into Rome. Beginning on the short side facing the Palatine Hill (the west side), we see Constantine’s departure from Milan. Then, on the south side, his siege of the walled city of Verona and the Battle of the Milvian Bridge are represented. His entry into Rome is on the east side, so the Colosseum will be on your right, and finally, when your back it to the Colosseum, you will see his address at the rostra, or speaker’s platform, and his liberal distribution of gifts to the Roman People on the long north side.

Other sculptures from the time of Constantine include

1) images of the goddess Victory and a river god in the spandrels adjoining the central and side arches;

2) captives and more Victory goddesses represented on the bases of the eight columns around the arch; and

3) tondi of the Sun god and Moon goddess on the short sides of the arch. The importance of the Sun god was underscored since Rome’s tallest statue, originally of Nero but recrafted to represent the Sun, stood visible through the arch looking north. It gave its nickname, the Colossus, to the adjacent Colosseum.

If we come to the arch thinking especially of Constantine’s reputation as the man who, after a divine vision and divinely-supported victory, Christianized the Roman Empire, it is surprising that there is no Christian imagery on the arch, while pagan deities and pagan rites are all over it. But the arch also carries an inscription on identical panels at the top of both of the main façades. Might the inscription cancel the pagan themes on the Arch and declare Constantine’s devotion to the Christian God?

The inscription reads as follows:

To the Emperor Caesar Flavius Constantine, the Greatest, Pius, Felix, Augustus:

inspired by (a) divinity, in the greatness of his mind,

he used his army to save the state by the just force of arms

from a tyrant on the one hand and every kind of factionalism on the other;

therefore, the Senate and the People of Rome

have dedicated this exceptional arch to his triumphs.

The inscription is invariably cited in the polemics over the timing, sincerity, and degree of Constantine’s Christian piety, but its contribution to the debate is itself disputed. It calls Constantine “pious,” which might point to his new faith, but the epithet of the pagan Aeneas was “pious,” so there is no reason to infer that “pious” refers to Christian piety in particular, especially since it occurs in a list that includes other traditional titles such as “Caesar,” “the Greatest,” “Felix,” and “Augustus.”

“Inspired by (a) divinity” might refer to a Christian inspiration in some other context, but why would it do so here? The ancient Romans saw the world as inhabited by divinities of every variety. If “divinity” might refer to the God of whom the arch contains no trace, would it not more likely refer to one of the several pagan divinities that do appear on the arch? The Sun god would be a likely candidate.

Or perhaps the word was chosen precisely because of its ambiguity. The language of the famous Edict of Milan, which called for religious toleration, was similarly noncommittal; it referred to “whatever divinity whatsoever there is in the seat of heaven” (Lactantius, De Mort. Pers., ch. 48). The inscription declares that Constantine was opposed to QUOTE “every kind of factionalism,” which supports the observation that the arch seems determined not to wade into the troubled waters of religious sectarianism.  It is certainly much more ambiguous than the gleaming cross in the sky Eusebius would later say had appeared to Constantine’s entire army in broad daylight on the day before the Battle of the Milvian Bridge.

One way of explaining the arch’s silence about Christianity while bringing it closer to conformity with the view of the work by Raphael and Bernini is to say that Constantine did not judge the time quite right to announce his new beliefs on public architecture in the center of a pagan city. Similar reasons might explain why the first large churches in Rome were all on the periphery, not near the numerous pagan shrines and temples that populated the Forum. These are reasonable considerations, but Eusebius’s story has Constantine fighting under the sign of a visible cross in the sky and winning victory thanks to the armed angels that accompanied him. Wouldn’t the experience of such a miracle followed by a decisive victory attributable to his open embrace of Christian symbols reassure Constantine that he could and should loudly proclaim this powerful new God? Don’t the calculations of prudence change when we really believe an omnipotent God stands ready to defend us through thick and thin?

Still another way to maintain that Constantine was a devout Christian and beneficiary of a miraculous vision before the battle is to say the Senate designed the arch and chose the values it represents, perhaps to keep Constantine’s new views from gaining traction in the ancient city. It could be so, though it would seem odd for a relatively weak Senate to challenge the decided views of such a powerful conqueror, just as it would be odd for such a man to leave standing a gross misrepresentation of himself. He returned to Rome later, in 326, and he could easily have had the inscription changed without undertaking the hard work of redoing the sculpture.

My own inkling is disappointingly simple. The discordant messages of the arch and the later Christian representations of Constantine are merely more evidence of the metamorphosis of the old pagan world into a new world saturated with Christianity. This metamorphosis had barely begun when the arch was built, while, for example, the Room of Constantine and Bernini’s statue were designed a millennium after it had become complete. Eusebius was a major contributor to this development, but his work came two decades after the arch and looks to me like a way of going back and reinterpreting Constantine’s victories. Only after Constantine had made himself the most powerful man in the world and the new faith was becoming official was it possible to give a Christian account of his victories. As Eusebius put it in his Life of Constantine, written just after Constantine had died, “Thus then the God of all, the Supreme Governor of the whole universe, by his own will appointed Constantine, . . . to be prince and sovereign: so that, while others have been raised to this distinction by the election of their fellow men, he is the only one to whose elevation no mortal may boast of having contributed” (I.24). This new approach to “history,” which did not always scruple to weed out legend, persisted and remained available to the popes of the Renaissance, when they designed the magnificent room that shows Constantine as a beneficiary of a just God and a servant of His Church. But the makers of the arch, which was built immediately after Constantine’s victory, knew nothing of this. Nor, I suspect, did Constantine himself.

But before leaving the arch, we note that it has stimulated engaging debates also over the quality of its sculpture. This question becomes even more important if artistic excellence is considered a part of what makes a culture admirable.

The Siege of Verona as portrayed on the Arch of Constantine in the fourth century

As noted above, the Constantinian carving seems artistically inferior to that of the spolia seized from the earlier monuments of Trajan, Hadrian, and Marcus Aurelius. The figures are far less lifelike, and the relative scale of subjects is odd or even comic: soldiers with heads as large as their torsos are sometime as tall as the walls of the city they are attacking. Thus the argument has been made, at least as early as Vasari in the Renaissance, that the arch offers an excellent opportunity to see the artistic decline during the two centuries that separate the Constantinian carvings from the spolia that surround them, and the distinguished art historian Bernard Berenson revived this argument in the strongest terms. Perhaps the extensive “borrowing” of earlier sculpture is an admission of decline.

Constantine addresses the Roman People as sculpted on his Arch in the fourth century

Almost needless to say, others have found Berenson too judgmental or, at least, complained that his judgments did not take adequately into consideration that Constantine’s artists had to do their work in a very narrow band, which compelled them to shrink the architecture and expand the people. And perhaps it was not the quality but the purpose of art that changed. If the goal of art was no longer to imitate nature, it could not be blamed for doing so badly, could it? Perhaps art then strove to be symbolic rather than imitative. In this case, the size of figures might indicate their importance, not their natural stature, for example. Shouldn’t a work of art be judged by its purpose, not that of some other age? Perhaps. We return later to this wonderful hornet’s nest of issues. In the meantime, the arch is a clear illustration of carvings of emperors in action from two different periods, and noting their differences—both in meaning and in artistic representation—is indisputably a good way to hone our powers of observation.

The arch does not prove that Constantine would not lead a Christian revolution in the years to come: his long reign was just beginning. But the dramatic events so prominent in Christian treatments of the emperor, both in literature and in art, are not even hinted at on the arch. It is largely traditional, at least in its political and religious content, even if it had to borrow older art to succeed in being so. It thus offers an alternative to the way we will see Constantine represented when, in just a few weeks, we will see him in the room Raphael devoted to him in the Vatican Museums.


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