The Arch of Constantine

William Storage  

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Life of Constantine

Details of the life of Constantine are helpful for understanding this monument, which includes a pictorial narrative of an episode in Constantine's life that many see as a turning point in western history.

According to the Vita Constantina, written by Eusebius shortly after Constantine's  death, Constantine was born in Moesia (Serbia) in about 272, based on his having begun his reign at the age Alexander the Great was at death, reigning almost 32 years, and being over 60 years old when he died[1]. But virtually all dates in Constantine's  life are disputed. Errors, omissions, and intentional misrepresentations have been identified in Eusebius's writings. Furthermore, some scholars have concluded that Vita Constantina was not finished at the time of Eusebius's death, and was hastily finished by another author. Eusebius and Constantine may have had a political motive for wanting to show Constantine to be older than he really was, although there is general agreement on the birth date given by Eusebius.

Constantine's  father was the emperor and tetrarch, Constantius Chlorus; his mother the famed Helena, venerated saint of the Orthodox Church. Constantine served - or was held as a hostage/good faith pledge[2] - under emperor Diocletian and then Galerius in Nicomedia (İzmit, Turkey). He was later reluctantly, says Lactantius,[3] allowed to join Constantius in Britannia and was there when Constantius died on July 25, 306. The army immediately proclaimed Constantine Augustus, although hereditary succession was not acknowledged as valid during the tetrarchy. Galerius initially contemplated a fight, but then submitted upon advice from his confidants. As with Eusebius, Lactantius's portrait of Constantine is of a godly, blessed prince, and of Galerius and the rest of Constantine's  opponents as "deranged", "wicked", and even "pernicious wild beast." This bias might call into question the accuracy of Lactantius's history.

Constantine returned from Britannia to Augusta Treverorum (Trier) as Augustus. In 307 he separated from his first wife or mistress,[4] Minervina, mother of his son Crispus, and married Fausta, the daughter of emperor/tetrarch Maximian[5]. Meanwhile in Rome, the Senate proclaimed Maximian's son, Maxentius  - who was also Constantine's  brother in law - emperor, and their rivalry began, or perhaps accelerated. This rivalry culminated in Maxentius's death at the famous Battle of Milvian Bridge, and Constantine's becoming leader of the western Roman world. The inscription on the Arch of Constantine describes Maxentius as a tyrant. The significant historians agree with this assessment, including the ancient pagan writer, Zosimus[6] - although it's possible that contrary views once existed but have not have survived.

Lactantius, tutor of Constantine's  first son, Crispus, reports that Constantine was commanded in a dream the night before the battle with Maxentius to cause the heavenly sign to be delineated on the shields of his soldiers. Lactantius describes the sign as being the chi-rho symbol,[7] now known as the Constantinian monogram assoicated with Christianity, although pre-Christian uses of the symbol existed. Eusebius's  more famous account of Constantine's vision, written twenty five years later, involves a giant cross in the sky, the words, En touto Nika (by this, conquer), and a personal visit from Christ.[8] Eusebius reports that Constantine attributed his victory to the God of the Christians and thereafter pursued a Christian life.

Traditional histories therefore hold that this event was the beginning of Constantine's conversion to Christianity. An opposing view holds that Constantine merely used Christianity as a political tool, and remained pagan until he was baptized on his deathbed - either too weak to protest or because he felt he had nothing to lose at that point. Available evidence shows both these opposing accounts to be incorrect on at least one point. Constantine, as shown by both Timothy Barnes[9] and Thomas Elliott,[10] had significant Christian leanings his entire life, including his early years. Thus a conversion sparked by his victory against Maxentius seems unlikely. Delayed baptism was common, given the belief held by some Christians that major forgiveness was divinely granted only once (pre-baptism), and thus it does not indicate a lack of commitment to Christianity[11]. Constantine clearly had little interest in the finer points of Christianity, as is obvious even later during the Council of Nicaea, where he failed to grasp the severity of the Arian/Athanasian debate. But failure to grasp its subtleties, to publicly state his allegiance, or to behave in a Christian manner does not preclude that he, like possibly his father and his mother, saw himself as a Christian.

Even after the time of his reported conversion, he seemed to have maintained interest in Sol Invictus and Hercules; and some degree of syncretization is plausible.[12] Constantine's exact position cannot be drawn from ancient texts or inscriptions. The reason for this is not merely that ancient sources are not trustworthy. Elliott illustrates that Constantine skillfully maintained neutral or ambiguous language in public propaganda even after the Christian writers (who preferred the view that he underwent a momentous conversion) report that he was fully committed to a Christian mission.[13]

Constantine's  victory over Maxentius left two augusti in charge of Rome - himself and Licinius. Licinius married Constantine's  half-sister, Constantia, in 313. At this time the two emperors agreed on a policy of religious tolerance, which resulted in the so-called Edict of Milan, reported to have granted freedom to all religions, although the text of this edict did not survive. Manicheanism (Manichaeism) seems to have been exempted from toleration, and was the object of subsequent persecutions.[14] Eusebius praises Constantine for an imperial edict to destroy the engines of impure superstitions such as a temple dedicated to the foul demon, Venus. He also praises Constantine for ordering destruction of the Temple of Aphrodite in Aphaca and for using the army to kill its priests. Thomas Elliott argues that Eusebius invented or grossly exaggerated Constatine's anti-pagan agenda, however, in order to encourage future rules to follow such a course. H.A. Drake similarly disputes Barnes position that the emperor was anti-pagan.[15] [16] Constantine's 323 decree that Christians were banned from participation from state sacrifices (Codex Theodosianus 16.2.5) might have pleased the clergy, but must also be counted technically as a restriction on religious freedom.[17]

Constantine's  family relationship with Licinius proved no more stable than that with Maxentius, both ties based on marriage with his sisters. In about 315, after what was likely a false charge by Constantine of an attempt on his life by Licinius,[18] the first battle of a civil war between troops of Constantine and Licinius occurred, resulting in a truce that lasted a few years and included provisions for sons of both emperors to be Caesars. After breakdown of this truce and two major battles, Constantine emerged as the sole ruler of the Roman world. Licinius fled from the final battleground, Chrysopolis, to Nicomedia. Both Constantia and Eusebius pled on Licinius's behalf; and Constantine agreed, guaranteeing safe conduct to Thessalonica. A few months later, coincidentally just after dispatch of the invitations to bishops for the first Council of Nicaea, Licinius and his son were both murdered.

Constantine's quest for a unified Christianity was not fulfilled in the first of many sessions of the Council of Nicaea. The Council was stuck on the matter of whether Christ was of the same essence or of the same substance as God the Father This problem persisted for years, resulting in numerous rewordings of the Nicene Creed. Its other products included rules concerning the date of Easter and many pronouncements of heresy upon various Christian sects.

On April 1, 326, Constantine issued a comprehensive edict on sexuality and morality that was totally unprecedented in the history of Rome. It made adultery, having concubines and elopement capital offenses punishable by specific and cruel deaths. Nurses who facilitated elopement, for example, would have molten lead pored down their throats. As Timothy Barnes[19] eloquently distills it, "this law disregards the natural appetites of men and women in favor of an abstract ideal of purity deduced from Christian tenets of asceticism, [and] rendered criminal the normal behavior of many Roman aristocrats." The law immediately became a tool of Romans seeking elimination of any personal or political opponent against whom a shred of evidence of indiscretion could be laid. Constantine's decorated son Crispus, consul and Caesar, soon became its victim. The specific accusation is lost to history, but legend holds that it involved an attempted rape of Fausta, his stepmother. This seems unlikely, based on geography alone; they lived many days travel from each other. Constantine sentenced his son to death, and Crispus was executed immediately.

Helena then convinced Constantine of Crispus's innocence, possibly pointing out that Fausta had an obvious motive for elimination of the heir, Crispus; and Fausta's death soon followed, either by execution or by suicide. Helena's famous pilgrimage to the holy land was no doubt a component of a program to replace public images of the Crispus/Fausta scandal with those more fitting to Christianity's imperial champion.

Despite the preceding example of legislation, it is inaccurate to say that Constantine generally made sweeping changes to Roman government favoring Christian beliefs. In some cases, he continued programs begun by Diocletian. His opinions and legislations vacillated, often granting mass amnesties. Suppression of paganism and incorporation of the Christian agenda into Roman government took decades, with a major milestone being the prohibition of all things pagan under Theodosius. The two primary sources on the final period of Constantine's reign give accounts that cannot remotely be reconciled. The pagan Eunapius[20], who claims Christians contributed to Alaric's invasion of Greece, sees him as bumbling, lacking strategy, and imposing ruinous taxes[21]. Eusebius sees him as a charitable and wise hero. Both agree that he provided increased financial and legislative support to Christians until his death in May, 337.

Eusebius's Vita Constantina reports that Constantine was baptized in Nicomedia weeks before he died. Jerome's translation of Vita added that it was the Arian bishop, Eusebius of Nicomedia, who performed the baptism. Other writers placed the baptism early, at around 312.[22] Orthodox Christianity's anxiety over the notion that Constantine was baptized by a heretic bishop seems to have given rise to ancient fictional accounts of the baptism[23].

Constantine's life may forever remain controversial. Ancient biographies are all marred by strong political and religious (pagan or Christian) bias[24]. Ancient authors had both the means and the motive for introducing fictions. Medieval and modern writers - even those with no such bias - reproduced these fictions, and thus they persist. Only in the last few decades has significant critical analysis been applied to the goal of extracting the real Constantine from propaganda, myth and legend. What seems to emerge is a figure who, during his 32-year reign, despite violent impulses and frequent reversals and self-contradictions, managed to continue the growth of commerce begun under Diocletian, maintain Rome's military and its borders, and restore a sense of unity in the wake of long years of internal conflict. His critics and proponents agree that Constantine also sought, for reasons about which there is great disagreement, to convert the empire to Christianity; and that this quest profoundly influenced the course of human history.

The Arch And Its History

No ancient sources mention the Arch of Constantine or any arch where it now stands. It appears in 16th century engravings by Du Prac, and in later engravings by Piranesi, Rossini, Lauro and others. In modern literature, Rodolfo Lanciani (1892) discussed the arch, specifying its location as the intersection of the via Sacra and via Triumphalis,[25] adjacent to the Colosseum. Platner's Topographical Dictionary of Ancient Rome (1920s) described the arch in detail,[26] noting that there is no historical basis for the name, via Triumphalis. He also wrote that the date of its completion is fixed at 315-316, based on the mention of the decennalia on the inscriptions of the side arches. Of course, the arch need not be the same age as the inscriptions, and the inscriptions only imply the decennalia on the basis of the inscription, votis X. Nevertheless the above date is accepted by all modern writers. Votis XX also appears in a nearby inscription. As on coins, this seems to be an ancient equivalent of many happy returns, foretelling the emperor's vicennalia ten years in the future. Scholars have long speculated that the arch itself originated in the time of Domitian or Hadrian. This idea lost favor in the 1930s, and was then rejuvenated in the 1990s by Alessandra Melucco Vaccaro. But the whole arch, with possible exception of part of its base, has recently been firmly dated to the fourth century by sound, scientific means, closing the popular issue introduced by Arthur Frothingham in 1912.

View from the northeast as recorded
 by Du Prac around 1500
View from the southeast as recorded
by Rossini in the early 1800s

 The arch is about 20 meters high, excluding any ornamentation that may have stood on its current roof, 25 meters wide and 7 meters deep. The central archway is 12 meters high, and the two side archways are 7 meters high. Eight fluted, Corinthian columns of yellow Numidean marble, probably taken from a building of the Flavian era when the arch was built, were attached to the arch, seven of which remain. The columns are ornamental and do not support any load. One of them is a modern replica, replacing the one taken by Pope Clement VIII in 1597, which now stands in San Giovanni in Laterano.

South face
(click pictures to enlarge)

North face

While certain portions of the sculpture that adorns the arch were carved specifically for Constantine, most of its sculpture can with confidence be traced to earlier periods (fig. 9). This does not mean that the older works were haphazardly selected, as the term spolia might imply; they appear to have been carefully chosen based on suitability to Constantinian propaganda, as first reported by Hans Peter LOrange.[27]

Identical inscriptions on both sides read and translate as follows:


To the Emperor Caesar Flavius Constantinus, the Greatest,
pious, fortunate, the Senate and people of Rome,
by inspiration of divinity and his own great mind
with his righteous arms
on both the tyrant and his faction
in one instant in rightful
battle he avenged the republic,
dedicated this arch as a memorial to his military victory.

Inscription on south side
(Link to large images of both inscriptions)


The phrase INSTINCTV DIVINITATIS, which does not occur in any extant literature prior to construction of the arch, has been the source of considerable debate. Suggested meanings include being inspired or prompted by a Divinity (Christian or pagan), or being inspired by divinity (e.g. "beauty is divine"). A close parallel to this wording, instinctus divinus, is found in Cicero's De divinatione, where it refers to foreknowledge of coming events, a meaning perfectly suited to the context of the inscription on the arch. Cicero's usage does not differentiate between root causes for such foreknowledge. Constantine knew of this piece by Cicero and quoted from it in his speech, Ad sanctorum coetum. It is likely that Constantine's usage (or, more accurately, the Senate's usage on Constantine's behalf) includes a nod to the god of the Christians and the god(s) of the pagans. But to a greater degree, it reflects Constantine's boasting that he had known that the Maxentius problem would have to be addressed sooner or later, and that he was justified in having taken swift action to remedy this problem. Interestingly, in the speech where Constantine cites Cicero, he does so to argue for a Christian interpretation of a pagan Sibylline prophecy. [28]

The marble blocks into which this inscription was set, along with those facing the rest of the arch, vary irregularly in type and color (fig. 6). This fact alone strongly supports a fourth century date for the arch. Such variation is not seen on any early imperial monuments. Likewise, the poor fit of pre-carved components seen on the Arch of Constantine, notes Mark Jones, would have been unthinkable on any Hadrianic or Domitianic monument. A vivid example of misfit pieces is seen in the discontinuities in the decoration of the entablature where blocks adjoin (fig. 7).

Irregular distribution of Carrara marble blocks (shown in red)
within the otherwise Proconnesian marble on the south face.

Discontinuities in entablature decoration

The eight Dacian captives, standing proud and handsome across cornices around the attic (figs. 16-19), may have come from Trajan's Forum, which was bounded by a large frieze discussed below. The statues undoubtedly date from the period from Domitian to Trajan, since they clearly portray Dacians. Carved in pavonazzetto marble, similar statues have been found in Trajan's Forum, including one on display in the Vatican's Braccio Nuovo. One of the Dacians is a modern (1731-2) replica. The remainder have restored hands and feet.

8 9
Color coding showing likely sources of spolia used in the arch:
Red - Trajan Yellow - Marcus Aurelius
Blue - Hadrian Green - Constantine and Licinius or Constantius

The Attic Panels

Most scholars agree that the eight rectangular relief panels in the attic are from an earlier monument dedicated to Marcus Aurelius. Whether the panels were ever set in place on such a monument is unknown; there is no numismatic or literary evidence for its existence. Frothingham concluded that at least two different arches had been the source of these panels; and that one of them had been dedicated to Lucius Verus, who was co-emperor of Marcus Aurelius for part of his reign. Frothingham saw two distinct styles in the panels, one more Hellenistic, the other he described as Roman style. Max Wegner reached a similar conclusion about their styles, using the terms klassischer Meister and barocker Meister[29]. In arguing for a Verus origin, Frothingham[30] noted that the rightmost panel of the north side (North face, panel 4 - fig. 11), a standard bears two portraits (fig. 13), whereas in South 4 (fig. 15), the standard shows only one portrait. He saw the two-portrait standard as evidence of his Verus hypothesis. He saw Verus, not Marcus, in the panel with the single-portrait standard because Verus, whose arch stood on the Vai Appia, was the key ruler in the Parthian war. He also sites as evidence the fact that there are two distinctly different styles of frames on the panels as well; and thought this could only result from their having originated on two different arches, ignoring the possibility that certain frame dimensions were not specified to separate teams of sculptors who produced the panels. Frothingham's work points out the difficulties encountered by past scholars, and the tendency, in the midst of exciting archeological discoveries, to leap to conclusions.

While his conclusions were hasty and poorly defended, Frothingham did make a number of original and useful observations that have been employed by later scholars. His argument for Verus as the subject of the single-standard panel was tortured, but its elimination does not rule out two monuments of Marcus Aurelius as panel sources, one of which was more accommodating of his slightly less than equal partner. Against such an argument, all the panels appear to have the same external dimensions. This would be an odd coincidence if they were built for two different arches. Recent scholars acknowledge different styles among the panels, but attribute them simply to variations between contributing sculptors styles.

Commodus was also at least once suggested as the subject of the original panels.[31] This also seems unlikely, based on evidence of his removal from one of them, the liberalitas scene discussed below. Whoever were the original subjects of the eight panels, they are now all Constantine. The current Constantine heads were replaced in 1732[32], presumably as restorations of earlier-recarved heads of Constantine. Three other panels, thought by most to be of the same series (thus a now-lost arch of Marcus Auerlius would have had twelve or more panels) are displayed in the Capitoline Museum. Johannes Sieveking, however, concluded that the three in the Capitoline were from an earlier arch than the panels now on Constantine's  arch[33]. This conclusion is accepted by some but not all modern scholars. Their external dimensions are the same as those on the arch.

Art historians have written lengthy arguments on the exact dates of the attic panels on the basis of stylistic elements and their content. They agree on the reign of Marcus Aurelius, but on little else. Determinations of exact dates for ancient works, or even judgments of relative age on the basis of sculpture style seem to me vastly overconfident, failing to address differences in artistic technique between several artists commissioned to work on the same piece. Most scholars date the panels as a group somewhere between 176 and 180.

I.S. Ryberg[34] and others maintained that the attic panels were intended to be read in order, and that they wrap around the arch in the same direction as the continuous frieze of Constantine wrapping the arch. This seems unlikely, given that the panels are a subset of those used on their original monument. It also seems unlikely that events in the life of Constantine could parallel those of Marcus Aurelius closely enough for an originally-cohesive story of Marcus to remain cohesive with his head replaced by that of Constantine.

Scholars now more or less agree on the following general categories for the panels:

North face, panel 1 adventus
N panel 2 profectio
N panel 3 liberalitas (largitio/congiarium)
N panel 4 clementia (submissio/justice)
South face, panel 1 Rex Datus
S panel 2 Prisoners brought before the emperor
S panel 3 adlocutio
S panel 4


The adventus panel (fig. 10) is generally agreed to represent the return of Marcus Aurelius from battle after his successful campaign against the Germans and Sarmatians in 176. P. G. Hamberg[35] referred to this scene as "allegorical", a term that did not sit at all well with Karl Lehmann.[36] Hamberg's basis was that Marcus is the only mortal character in it, although it seems to represent a real location, the Temple of Fortuna Redux on the Via Latia in the Campus Martius. Its primary focus is the interaction between Marcus and Roma[37] on the right side. Mars stands behind the emperor; the war is over. Victory flies over Marcus's head, above two lesser deities or personifications in the background.

Attic North, left
Dacian, Adventus, profectio
Attic North, right
liberalitas , clementia, Dacian
liberalitas detail
clementia detail
Attic South, left
Rex Datus, prisoners
Attic South, right
adlocutio, lustratio
Dacian captives
17 18 19


The adventus is paired with a profectio scene (fig. 10), indicating that it represents Marcus's departure for battle in 169. The emperor wears a traditional short tunic and mantle, the heel of his right foot lifted to signal impending motion. A reclining personification of the road Via Flaminia in the case bids him farewell. The identification of the personified road is certain; earlier coins depict parallel scenes and include labels for the relevant roads. Virtus, dressed for travel as compared to the nearly identical Roma, who usually bears one breast, will presumably accompany the emperor into battle. A genius senatus, bearded and wearing a toga, stands behind Marcus. A man, usually agreed to be Claudius Pompeianus, Marcus Aureliuss son-in-law and advisor, stands to his left, barely visible in this relief. Earlier scholars, such as Stuart Jones[38] and Eugenie Sellers Strong,[39] identified this assistant as Bassaeus Rufus instead of Pompeianus, who seems to be generally accepted today. Wegner considered this relief to be in the klassischer style, however the treatment of soldiers and horses does not seem to fit that description. L'Orange identified the structure in this scene as the Arch of Domitian in the Campus Martius. Note that the arch is crowned with a chariot drawn by elephants.

In third position on the north face of the arch (fig. 11) is a scene of public largess, most likely associated with the liberalitas of 177, centered upon Marcus Aurelius and his son Commodus after their joint victory of 176. Pompeianus is again present, but Commodus is not. A conspicuous void in the relief probably reveals where he once sat on a sella curulis like his father. A fragment, likely the remains of his foot appears on the podium (yellow arrow in fig. 12). Further evidence of recarving of this part of the relief is the fact that the bottom half of the toga of the man standing on the step is carved in lower relief than that of his upper half, and that this difference is not easily explained by differential weathering of the panel. Several of the heads are restorations. The head of a boy riding piggyback on his fathers shoulders is missing. The surface finish of the recarved area is also noticeably rougher than that seen in the rest of the relief. Commodus, subject of a damnatio memoriae, also appears to have been removed from one of the panels on display in the Capitoline Museum (fig. 20).

 Panel number four, clementia (fig 11), on the archs north side shows Marcus Aurelius seated on a tall stool (sella castrensis) with his right-hand man Pompeianus standing at his side. Soldiers with flags and standards surround two barbarian prisoners, an exhausted older man and a young boy who props him up. Some writers have concluded that this is a barbarian chieftain and his son, who, full of grief, are subjugating themselves. This panel also appears to bear the mark of Commodus's damnatio. The center of three standards (an imago) holds two portrait images. The uppermost of these is in good condition, but the face on the lower one is completely worn or chiseled away. Differential erosion seems unlikely. Eric Varner noted that the subject of the lower one (fig. 13) appears to be cuirassed and includes a paludamentum, the cloak worn by a Roman general.[40] Thus, as Wegner suggested, the two portraits probably originally showed Marcus and Commodus, with Commodus having been intentionally obliterated. 

The south face attic begins with a Rex Datus scene, wherein a vassal king is either crowned before or introduced to the Roman soldiers. The event indicates that a peace treaty has been signed and that a former enemy is now an ally. Early scholar Giovanni Bellori,[42] who examined the piece in 1690, also saw it as showing coronation of a vassal king, although he concluded that the emperor was Trajan. Frothingham concluded that the original emperor was Lucius Verus, on the grounds that no coins of Marcus Aurelius depict a Rex Datus, whereas several coin types of Verus do, including legends such as rex armeniis datus. One minor peculiarity of the scene is the lack of the kings subjects, who would have witnessed such a ceremony, possibly omitted simply due to space constraints. The head of the king is a modern restoration.

South face panel two (fig 14) depicts enemy soldiers dragged before the emperor in the field, as indicated by the tree on the right side of the image. One of the captives is still resisting while the other has accepted the futility of doing so. The emperor wears a tunic, a paludamentum and leggings. Once again, Pompeianus, similarly dressed, stands beside him. The panel has been broken in two and repaired.

The adlocutio scene (fig 15) depicts a typical episode of the emperor motivating his troops at the beginning of a military campaign. His left hand, now missing, probably held a lance. His right hand is raised in gesticulation. Seven soldiers, each in different types of uniforms, including scale armor and chain mail, listen intently to their leaders words. The top part of the panel, including the tops of the standards, is a restoration.

Lustratio is a celebration with the army at the beginning of a military campaign, probably originally referring to ritual purification before battle. The emperor presides over the ceremony, using a portable tripod-mounted altar. A bull, sheep, and pig will be sacrificed in a rite called the suovetaurilia, in which Mars would be expected to purify the land. Soldiers with flags and ensigns stand behind a musician and an incense bearer (camillus). Pompeianus appears behind Marcus/Constantine, with his head above that of the bull. The upper quarter of the panel, showing tops of the wreaths and the eagle atop the standard, is a restoration. The portrait in the imago on the left is too weathered to support identification of its subject. Art historians frequently debate the style of the lustratio scene. Most agree that it represents a more modern departure from the styles of the other seven panels on the arch. 

Remnants of the Great Trajanic Frieze 

Many scholars agree that the four large reliefs, each in two panels about three meters high, originated in a 30 meter long frieze in the Forum of Trajan. Two are on the short sides of the attic(figs. 21, 22), and two more the most interesting and best preserved are within the central arch, nearly at ground level. Most authorities agree that they originally depicted Trajan and date to early Hadrianic times. Others have concluded that Domitian was the subject of the reliefs in the central arch, and that they somehow, like the Cancelleria reliefs, escaped mutilation during the two short periods of Domitian's damnatio. One objection to their originating in the Forum of Trajan is that it was reported to be still intact in the time of Theodoric, long after the Arch of Constantine was built.

The relief on the west (figs. 23, 24) side shows Trajan, on horseback, with his mantle billowing in the wind, above a fallen Dacian who cowers below. Another Dacian faces the emperor, on his knees, begging for the clemency that we viewers know will be granted. To Trajans left is an armored Roman, who seems to be on the verge of slashing his victims throat. Trajan's participation in the battle is presumably symbolic; he is not wearing a helmet. Similar portrayals of equestrian emperors, without helmet, in the middle of battle scenes, appear fairly often, such as the 3rd century battle scene on the Ludovisi sarcophagus.The inscription above the scene reads Liberatori Urbis (liberator of the city).

Trajanic frieze panel
Attic West
Attic East
Central bay West
Central bay West
Central bay East

The relief on the other side of the central bay (fig. 25) is unusual because it combines two scenes that are separated by time and space. Trajan stands between Roma (or Virtus) and Victory, who is about to place a wreath on his head. Immediately behind Victory, Roman soldiers on horseback trample and defeat wavy-haired Dacians. Diana Kleiner notes that this conflation of adventus and battle is not seen in earlier imperial art, although it does appear in contemporary art of this and earlier periods, thus this relief marks a turning point in state art.[43] The inscription Fundatori quietis (founder of peace) appears above the relief.

The Trajanic reliefs on the ends of the arch, at attic level, both depict battle scenes from the series of Dacian wars that ended in 106. The one on the east side includes buglers, Romans on horseback, and several falling or fallen Dacians. The western relief is of an ambush, showing that the crude weapons of the Dacians are futile against the advanced weaponry and armor of the Romans.

The Tondi of Hadrian and Constantine

Eight circular frames, each about 2.4 meters in diameter, enclose hunting scenes on the north and south faces of the arch. Each roundel (tondo) has a flattened bottom, apparently resulting from an attempt by the builders of the arch to achieve a more harmonious fit on the face the arch, providing adequate spacing between the tops of the roundels and the inscriptions above them. This reasoning, of course, presumes that the roundels were not built specifically for the arch. Mark Wilson Jones suggests that the distortion of the roundels also shows that a structural proportion scheme took precedence over artistic detail.[43] This may be the case, but a calculation or measurement error stemming from a hasty engineering effort could have produced the same result regardless of priorities. 

A facing in porphyry marble, a material not used on early imperial monuments, still surrounds a pair of roundels (figs. 27, 28). Near the roundels where the porphyry is missing, one can easily see that the backing masonry has been chopped away. This is seen by some as evidence that the arch was repurposed in Constantinian times. However, this condition really indicates merely that the roundels were initially not designed to be in their current position. Their use may have not been initially planned at all, or their desired location or even projection from the structure of the arch may have changed during construction of the arch.

26 27 28
29 30 31
32 33 34

Early twentieth century scholars, such as Sieveking and Stuart Jones[45] concluded that the roundels originated in the Flavian period, possibly from the Gens Flavia, and that some of them were subsequently recarved under Claudius Gothicus.[46] Their reasoning was complex, and was revealed to be overly so when Occam's razor appeared in the form of the identification of Antinous on one of the tondi, along with acknowledgment of Hadrian's fondness for hunting. The earlier scholars also saw the roundels on the south face to be carved by a different sculptor than those on the north side. This notion was dispelled by Margarete Beieber,[47] who noted that the north and south faces of many other monuments show equivalent differences due to weathering and mold growth.

Most now agree that the original heads of the protagonist of the roundels was Hadrian. Weathering and other damage prevents identification of the head that replaced Hadrian's, however. Constantine would seem to be the likely choice, although some of them may have been recut into his companions or family members. Both Constantius Chlorus and Licinius have been proposed for some of the figures, although Licinius seems to be favored in recent literature.

The first roundel on the north face (fig. 26) shows a boar hunt. The figure at top left appears to be Antinous, although in atypical clothing. The recarved emperor's head in this scene is easily identified as Constantine. Roundel 2 (fig. 26) shows a sacrifice to Apollo. The recarved emperor in this scene is clearly not the same as the one in the preceding roundel; reasonable candidates are Constantius and Licinius. Roundel 3 (fig. 27) shows a lion hunt, possibly depicting Licinius. Roundel 4 (fig. 28) shows a sacrifice to Hercules, whom Constantius claimed as an ancestor. A small figure of Victory appears at Hercules left side.

The first roundel on the south side noting that their current order may be unrelated to the order in which they appeared on an earlier monument depicts a departure for a hunt (fig. 29). Roundel 2 shows a sacrifice to Silvanus (fig. 30). Roundel 3 (fig. 31) shows the action of a bear hunt, with number 4 (fig. 32) showing sacrifice to Diana.

The two roundels on the short sides (figs. 33, 34) of the arch are substantially different from those on the north and south faces. Their circular bottom edges have not been reworked; and their style and content is different. Art historians in the early 20th century were quick to point out the poor quality of these roundels in comparison to the earlier sculptures. Modern critics acknowledge that the Constantinian artists had a less realistic style, but there is little value in assigning quality ratings to the works. Associating a decline in artistic quality with hard times in the empire is a flawed approach, as is seen by the impressionistic and veristic portraiture of the mid third century. Associating a decline in structural workmanship with hard times, on the other hand, appears to be valid.

The image on the east face depicts Sol in his quadriga, a four-horse chariot. The east end roundel shows Luna in her biga, a two-horse chariot. The moon image is above a section of the giant frieze of Constantine (described below) where Constantine's  first son, Crispus is shown in military triumph. Some have suggested that this arrangement was intentionally meant to describe Crispus as a reflection of Constantine as the moon is a reflection of the sun. Bill Thayer notes the irony of this metaphor: the moon once full wanes to nothingness, which is what happened to Crispus.[48]

The Frieze of Constantine

Despite the reference to Constantine's  victories in the main inscription, it is technically incorrect to refer to this arch as a triumphal monument, as Constantine never claimed a triumph after his civil-war victory over Maxentius. The Constantinian frieze shows a sequence of specific historical events, but does not include triumphal scenes. Traditionally, the style of rendering, including squat bodies and repetition of identical figures has been considered by art historians to merely reflect inferior artistry, although acceptance of the role of evolving goals of the artist and its patron also warrants consideration.  

The frieze wraps around the lower arch above the side passageways, highlighting significant and pivotal moment in Constantine's  career during and after his victory over Maxentius.

It starts on the west side, adjacent to the Palatine Hill. This section depicts Constantine riding his chariot (fig. 36), and his army departing Milan to attack Maxentius. Maxentius, the tyrant mentioned in the archs inscription is about to be defeated at the Milvian Bridge outside Rome's gates. The procession includes soldiers, some with helmets, some with Pannonean caps, a horse, a camel, musicians with horns, and imaginifers.

The story moves from left to right, continuing on the south side with the siege of a city, probably Verona (fig. 40). Victory crowns Constantine, who, now missing half his head, is surrounded by bodyguards. The emperor's army is mainly in a defensive posture, against the citys militia, who hurl stones and spears. One victim is falling from the city walls, while a lone Roman at far right storms the walls. This frieze panel includes an artistic device much more common in previous Christian art than in earlier Imperial or Republican state art: hierarchy of scale. Constantine is almost twice the size of his soldiers.

Complete frieze showing Constantine's victory and liberalitas, counterclockwise from its start on the west end
36 37 38
39 40 41
42 43 44
45 46 47
48 49 50
51 52 53


The next scene (fig. 42) shows the climactic battle of the Milvian Bridge - Constantine's  victory is a fait accompli with the presence of Victory and Virtus. Constantine, now missing from the frieze, was in the boat immediately to the right of the River God, adjacent to the bridge at bottom left. His enemies are drowning in the river Tiber, having been overtaken by Constantine's  soldiers along the top of the frieze. Musicians celebrate the victory at far right (fig. 44).

The short eastern side, now heavily damaged, shows the triumphant emperor's entry into Rome though not a triumphal procession (figs. 45-47). He sits on a throne (cathedra) that is part of a quadriga.

The north side frieze begins with Constantine addressing the citizens of Rome at the Rostra. He is the only figure shown completely frontally (fig. 49). Surrounded by men in togas, Constantine takes center stage. This hieratic representation of the emperor on high suggests a new concept of sovereignty and lordship (dominus), a near deification of Romes first citizen. This trend toward divine worship began with Augustus and would continue through the reign of Theodosius I. The impact of this representation of the emperor on the imagery of Christ Pantocrator in Christian art is the subject of considerable scholarly debate.[49]

Details of the Rostra and its surroundings are clearly identifiable. The Basilica Julia can be seen on its left side (fig. 48), with the Arch of Septimius Severus on its right. Five columns appear directly behind the Rostra. Diana Kleiner identifies these as belonging to the monument of Diocletian's Decennalia. Constantine appears between two statues on pedestals. On viewer-left is Marcus Aurelius, seated and wearing a toga. The other statue depicts Hadrian, with typical hair style and beard, holding a globe in his right hand. This setting informs viewers that Constantine belongs to the line of great emperors from the past. He thus differentiates himself from his immediate predecessors, the tetrarchs. Some writers have also suggested that the three young boys in the scene, uncommon in state sculptures, were meant to foster the idea that Constantine, who had three sons who were Caesars, would return to a dynastic succession model.

The last scene (figs. 51-53) recalls Marcus Aurelius in the liberalitas attic panel, overseeing the distribution of gifts to the public. Again Constantine is in the exact center of the frieze, this time seated on a podium (his head is missing). The similarity to Christian depictions of the throned Christ surrounded by disciples - intentional or coincidental - is obvious. Constantine's  right hand holds a tessera with slots for coins, some of which are falling out to be caught in the toga of a senator who gazes up at his benevolent leader. Four small rectangular scenes are enclosed within the borders of the frieze. These all depict distribution of money and the associated record-keeping.

Other Constantinian Art

The spandrels above the central and side arches both contain reliefs that were carved into the already-erected arch. Four images of Victory (e.g. figs. 57, 58), each with a different seasonal genius adorn the main bay. The spandrels of the side bays have different views of the river god.

The socles are also decorated with fairly typical themes including captives being lead by Roman soldiers and Victories standing about captive enemy soldiers (figs. 63-68). LOrange was able to link the pedestal scenes to specific enemy armies. Weathering damage, mold, and the protective fencing that now encloses the arch prevent easy viewing of the details.

Details from some of the spandrels
55 56 57
58 59 60
61 62  

Details from some of the socles
63 64 65
66 67 68


 Structural Proportion Models

The affects of fondness for numbers on the architecture and literature of the ancient world is understated in modern analyses. Notwithstanding the fact that some of those dedicated to studying dimensional proportions in ancient monuments have a propensity to find relationships whether or not they were intended by designers[50], some degree of proportional sophistication has been found in the Arch of Constantine.

Mark Wilson Jones, who analyzed its dimensions in great detail in several papers, notes for example, that the column height is equal to the axial width of the flanks, the height of the main passageways imposts, and the intercolumniation of the central fornix, within the tolerance of dimensions for like features. In other words, the variation between heights of two columns is similar to that between a column and the height of the central passages imposts. Other primary dimensions occur in ratios of two to one, three to one, and three to four. For example, the base of the columns is one half their height above the ground. The height of the entablature is one half the length of the monument. The column height is one third of its length. The width of the lateral fornix is two thirds of the width of the central fornix. All of the above ratios are accurate to a tolerance of about one percent. Readers interested in a thorough analysis of arithmetic ratios and geometrical schemes proposed for this monument should consult recent works by Mark Wilson Jones.[51]

Some proportion ratios found in the structure


More Information

Readers interested in the life of Constantine might enjoy the following books. Be aware that nearly all writings on Constantine, both ancient and modern, suffer from Christian or anti-Christian agendas. Only by vigorous skepticism and application of analytical discrimination of reported details and cautious synthesis can we have any hope of reconstructing details of Constantine's  life. A few of my favorites are:

Constantine and Eusebius (1981)
by Timothy D. Barnes

 Constantine and the Bishops: The Politics of Intolerance (Ancient Society and History)
by H. A. Drake (2002)
(Note that Drake and Barnes have reached very different conclusions)

by Samuel N. C. Lieu (Editor), Dominic Montserrat (Editor) (2005)

Life of Constantine (Vita Constantina) (Clarendon Ancient History Series)
by Eusebius, with introduction by Averil Cameron and Stuart Hall

An extremely useful reference to ancient texts that deal with Constantine is the prolegomena of Ernest Cushing Richardson's 1890 translation of Vita Constantina. It is available online at the Christian Classics Ethereal Library.  

Many books on Roman ruins and history of art discuss the Arch of Constantine. Several of these appear in the footnotes for this page. Be aware that many of the classics that deal with Roman art history contain outdated information on the arch. Two current books that I recommend highly are:

Roman Sculpture (Yale Publications in the History of Art) (1994)
by Diana E. E. Kleiner
(This is by far the best and most complete guide to Roman sculpture in existence, and does not suffer at all from the obtuse language plaguing much of the art history world.) 

Mutilation and Transformation: Damnatio Memoriae and Roman Imperial Portraiture (2004)
by Eric R Varner

Recommended online sources:

Wikipedia: Constantine I and Arch of Constantine

Constantine at De Imperatoribus Romanis

Arch of Constantine at Bill Thayer's site

Rene Seindal's Photo Archive

Arch of Constantine at Bluffton University



[1] Eusebius, Vita Constantini 1.8 and 4.53

[2] Zonaras, Compendium of History 12.33

[3] Lactantius De Mortibus Persecutorum Ch. 24. Fletcher translation available online at the Christian Classics Ethereal Library.

[4] Whether wife or mistress is disputed, and is the subject of many modern papers.

[5] Panegyrici Latini 6 (ed. Baehrens, Mynors)

[6] Zosimus, New History. London: Green and Chaplin (1814). Book 2  Available online at the Christian Classics Ethereal Library.

[7] Lactantius De Mortibus Persecutorum, Ch. 44. Roberts/Donaldson translation available online at the Christian Classics Ethereal Library.

[8] Eusebius, Vita Constantina 1. 28-29

[9] T.D. Barnes Constantine and Eusebius Cambridge, Mass. 1981. ISBN-13: 978-0674165311.

[10] Thomas G. Elliott "Constantine's Conversion: Do We Really Need It?" Phoenix, Vol. 41, No. 4. (Winter, 1987), pp. 420-438.

[11] Richard Rubenstein (When Jesus Became God Harcourt Inc. 1999, p.70) expresses this well: A good emperor would find himself compelled to choose between losing heaven and losing power Constantine was by no means finished either with power or with committing the sins necessary to retain it.

[12] I am not citing pagan imagery on coinage as a basis for this. Baynes (Constantine the Great and the Christian Church, 1972, ISBN-13: 978-0197256725) and others have shown that coin imagery is not a reliable indicator of the emperor's beliefs.

[13] Thomas G. Elliott "The Language of Constantine's Propaganda," Transactions of the American Philological Association (1974 - ), Vol. 120. (1990), pp. 349-353

[14] Manicheanism is specifically addressed as being banned in the Codex Theodosianus, although in chapters attributed to Valentinian and Valens.

[15] H. A. Drake. Book Review: "Constantine and Eusebius", The American Journal of Philology, Vol. 103, No. 4. (Winter, 1982), p. 464.

[16] H. A. Drake. Constantine and the Bishops: The Politics of Intolerance, The John Hopkins University Press, 2000. Drake's evidence for intentional ambiguity in Constantine's  propaganda stands, regardless of the validity of his analogy between ancient Rome and modern governments, and the scathing criticism of his work by Barnes.

[17] See Michele R. Salzman's "'Superstitio' in the Codex Theodosianus and the Persecution of Pagans" (Vigiliae Christianae, Vol. 41, No. 2. Jun., 1987, pp. 172-188) for a discussion of apologetics/polemics and the gradual transition under Constantine from tolerance of paganism to persecution of it.

[18] Anonymous (Anonymi Valesiani) Origo Constantini Imperatoris Ch. 5

[19] T.D. Barnes. Constantine and Eusebius Cambridge, Mass. 1981, p.220.

[20] Eunapius, as brought forth by Zosimus, Historia Nova

[21] Zosimus and Aurelius Victor (Epitome de Caesaribus 41.16) agree on this point.

[22] Fowden, Garth "The Last Days of Constantine: Oppositional Versions and Their Influence," The Journal of Roman Studies, Vol. 84. (1994), pp. 146-170.

[23] Conversio Constantini in the Actus Sylvestr. The book, Il battesimo di Costantino il Grande. Storia di una scomoda eredit by Marilena Amerise, (Hermes Zeitschrift fr klassische Philologie, Einzel-schriften, Heft 95) examines this at length. Timothy Barnes gives this book a very negative review on the basis of poor scholarship. Jan Willem Drijvers is less negative, but finds its main argument unconvincing. Both reviewers agree that the topic warrants more investigation.

[24] While it is inaccurate to say that there was no distinction between religion and politics in late imperial times, it is worth noting that the boundary was less solid and drawn differently than today's separation from church and state in modern government.

[25] Rodolfo Lanciani Pagan and Christian Rome, Houghton, Mifflin and Company, Boston and New York, 1892

[26] Samuel Ball Platner. A Topographical Dictionary of Ancient Rome. London: Oxford University Press, 1929. Available online at Bill Thayer's site.

[27] H. P. L'Orange; A. von Gerkan. Der Spatantike Bildschmuck des Konstantinsbogens 1939. ISBN: 3110022494

[28] Linda Jones Hall reads the same evidence as indicating intentional ambiguity: "Cicero's instinctu divino and Constantine's instinctu divinitatis : The Evidence of the Arch of Constantine for the Senatorial View of the "Vision" of Constantine". Journal of Early Christian Studies 6.4 (1998) pp. 647-671.

[29] Wegner, M. Archologischer Anzeige,. 1938 col. 155.

[30] A. L. Frothingham. "Who Built the Arch of Constantine? III." The Attic, American Journal of Archaeology, Vol. 19, No. 1. (Jan. - Mar., 1915), pp. 1-12.

[31] M. Cagiano de Azevedo citation in Eric. R. Varner: Mutilation and Transformation. Damnatio Memoriae and Roman Imperial Portraiture. Leiden and Boston: Brill, 2004. ISBN: 90-04-13577-4.

[32] Sydney Dean, Editor. Journal of American Archaeology. July-December, 1920. Archaeological News reports that in Bulletino della Commissione archeologica comunale di Roma, C. Gradara published an excerpt for the diary of Pietro Bracci in which Bracci states that he carved new heads for the emperors and other figures in the attic reliefs, along with new heads and hands for seven of the Dacian captives and one completely new Dacian.

[33] As reported by Platner in his topic on Arcus Constantini.

[34] Inez Scott Ryberg. Panel Reliefs of Marcus Aurelius (Monographs on archaeology and the fine arts, 14) 1967. ASIN: B0006BQ1JW

[35] Per Gustaf Hamberg Studies in Roman Imperial Art Almquist, Uppsala 1945, ASIN: B0007IWWTM

[36] Karl Lehmann Review of Studies in Roman Imperial Art, in The Art Bulletin, Vol. 29, No. 2. (Jun., 1947), pp. 136-139.

[37] Jocelyn Toynbee maintains that this god is Virtus, not Roma, on the basis that Roma stays in Rome while Virtus accompanies the emperor to war, bringing him home victorious. J. M. C. Toynbee. Review: Panel Reliefs of Marcus Aurelius The Journal of Roman Studies, Vol. 58, Parts 1 and 2. (1968), pp. 293-294.

[38] H. Stuart Jones. Notes on Roman Historical Sculptures Papers of the British School at Rome, III, 1906. pp 213-271.

[39] Eugenie Sellers Strong (Mrs. Arthur Strong) Roman Sculpture from Augustus to Constantine, Duckworth and Co. London 1907 reprinted by Hacker Art Books, New York, 1971, ISBN-13: 978-0878170531. This book is rather outdated.

[40] Eric Varner. Mutilation and Transformation. Damnatio Memoriae and Roman Imperial Portraiture. Leiden and Boston: Brill, 2004. ISBN: 90-04-13577-4.

[42] G.P. Bellori Veteres Arcus Augustorum Triumphis Insignes Ex reliquiis quae Romae adhuc supersunt cum imaginibus triumphalibus restituti. Rome, Jacopo de Rossi, 1690.

[43] Diana E. E. Kleiner. Roman Sculpture. Yale University Press, 1994. ISBN-13: 978-0300059489. Kleiner differentiates this conflation from the continuous documentary style of the Column of Trajan.

[44] Mark Wilson Jones. "Genesis and Mimesis: The Design of the Arch of Constantine in Rome." The Journal of the Society of Architectural Historians, Vol. 59, No. 1. (Mar., 2000), pp. 50-77.

[45] H. Stuart Jones "The Relief Medallions of the Arch of Constantine," Papers of the British School at Rome, Vol. III. MacMillan & Co., 1906. pp. 216-271.

[46] Claudius Gothicus did have a number of Flavian sculptures recut in his likeness. Constantine declared himself to be the grandson of Claudius Gothicus

[47] M Bieber. Mitteilungen des Deutshen Archaeologischen Instituts, Roemische Abteilung. 1911, p. 214.

[48] Bill Thayer. Crispus: the Moon at her Full. http://penelope.uchicago.edu/Thayer/E/Gazetteer/Places/Europe/Italy/Lazio/Roma/Rome/Arch_of_Constantine/W.html.

[49] Jas Elsner. Imperial Rome and Christian Triumph: The Art of the Roman Empire AD 100-450. 1999. ISBN-13: 978-0192842657

[50] See for example Richard Brilliant's bizarre proposal for a geometric design scheme for the Arch of Septimius Severus, which involves dozens of intersecting arcs.

[51] Mark Wilson Jones. See note 43. Also: "Principles of Design in Roman Architecture: the setting out of centralized buildings," Papers of the British School at Rome 57. 1989.

Publication history:
1/18/2007 - Originally posted on www.bstorage.com
3/16/08 - Moved to rome101.com with minor edits
10/31/08 - Minor punctuation changes, typos corrected.