The controversial history of the Arch of Constantine the Great in Rome

In the early 4th century AD, a power struggle for the Roman throne was playing out between two powerful men: Constantine I and Maxentius.

This was part of a broader conflict for control over the Western Roman Empire. It was the result of a series of decisions made by the previous Roman emperor. 

In AD 293, the then emperor, Diocletian, had divided the Roman Empire into four separate regions, each with its own ruler.

This was called the Tetrarchy system, and it was designed to both ensure orderly succession and provide increased stability across an unwieldy empire.

However, this system eventually faltered, especially when Diocletian chose to retire from his role.

He had hoped that the four leaders would continue his new system as he had designed it. 

Unfortunately, it actually led to all four men seeking to seize the throne for themselves.

Constantine, who had been ruling in Britain and Gaul, and Maxentius, who was based in Rome itself, defeated the other two challengers and remained as the last two contenders.

Maxentius was initially popular since he was the son of former Emperor Maximian.

However, his support had evaporated quickly due to heavy taxation. 

Then, in AD 312, sensing a moment of vulnerability, Constantine led his army towards Rome to trigger a final battle with Maxentius.

A famous story is told that the night before the battle, Constantine had a vision. In it, he reportedly saw a cross of light in the sky accompanied by the words "In this sign, you will conquer" (in hoc signo vinces).

The next day, Constantine adopt the Christian Chi-Rho symbol (☧) and ordered his troops to paint it onto their shields. 

On the 28th of October, at the Milvian Bridge, a crucial access point over the Tiber River into Rome, the two armies met.

Maxentius had actually been advised to remain within Rome’s fortified walls, but instead, he had charged out to meet Constantine’s forces at the bridge.

During the ensuing battle, as Constantine’s army pressed forward, Maxentius’ troops were forced towards the partially dismantled bridge.

As a result, the structure failed under the chaos of retreat, leading to Maxentius' drowning in the Tiber, along with many of his soldiers. 

Constantine’s victory left him as the sole ruler of the Roman state. It was also the beginning of his long journey to conversion to the Christian faith.

This shift led to his publishing the Edict of Milan in AD 313 AD, which mandated religious tolerance throughout the empire, including both paganism and Christianity. 

Shortly after Constantine's victory, he ordered the construction of a majestic arch to celebrate his achievement.

Triumphal arches like this had been built by Roman emperors for centuries, in order to both provide a new building for the people of Rome and to display visual propaganda to justify their rule.

In fact, two other arches are still standing in the Roman Forum, built by Titus and Septimus Severus.

Such monuments were designed to have an archway for the victorious soldiers and the emperor to march through on the official day of celebration. 

To this end, Constantine strategically placed his arch adjacent to the Roman Forum, between the Palatine Hill and the Colosseum, in the centre of the city.

It would stand approximately 21 meters high and almost 26 meters wide. It would have not just one archway, but three distinct passageways.

The large central archway would be flanked by two smaller lateral arches. Each of them would be framed by detached Corinthian columns on high pedestals. 

The Arch of Constantine was finally inaugurated in AD  315, three years after the pivotal Battle of Milvian Bridge.

Curiously, the central inscription states in Latin that the arch was dedicated to Constantine from the Senate and people of Rome.

However, in reality, it was Constantine that oversaw its construction. As a result, his meticulous design decisions and blatant propaganda are plastered all over the final product. 

While Constantine was keen to build his pet project, he had to face the harsh reality Rome faced in the early 4th century.

Almost fifty years of internal conflict and war had drained the empire’s resources. As such, building materials and skilled artisans were in short supply.

A project of this magnitude would be so costly that it might never be completed at all. 

To solve this problem, Constantine ordered the extensive use of spolia, or reused works, from monuments of earlier emperors.

The entire structure is adorned with sculptural decorations that include roundels, friezes, and statuary, which were often borrowed from earlier monuments of other emperors.

Scholars estimate that up to 80% of the decorative elements on the arch were sourced from earlier structures, including those commemorating the reigns of Trajan, Hadrian, and Marcus Aurelius.

The remaining 20% was brand new designs from Constantine’s own artisans. 

The resulting imagery on the arch was a confusing mix of both conflicting imagery and a wide variety of artistic quality.

For example, the sculptures taken from the time of Hadrian are far more intricate in their craftsmanship and rely on classical realism, whereas those crafted by Constantine’s men are more rigid and abstract.

Consequently, this blend creates a disjointed visual experience. 

A number of historians have argued that the conflicting artistic quality actually signifies a greater struggle that Constantine was trying to resolve.

On one hand, Constantine’s appropriation of these artworks might have been a strategic move to associate himself with the 'good emperors' of Rome’s golden age.

This would have helped him by legitimizing his rule in the eyes of the public.

So, the arch serves as a visual propaganda tool.  

The imagery of his role as a pious figure clearly showed his favor by the Christian God.

In its reliefs, senators, military personnel, and Roman citizens are depicted participating in and witnessing the emperor’s deeds, suggesting a collective endorsement of his rule.

As such, these images include glorified images of his triumph at the Battle of Milvian Bridge.

In addition, it includes scenes of battle, hunting, and sacrifices, which are allegorical, emphasizing themes of victory.

Through this imagery, Constantine conveyed his role as a benefactor of Rome, responsible for ushering in a new era of divine favor and imperial benevolence.   

Therefore, the arch employs allegorical figures, such as the winged victories and personifications of conquered provinces, which are typical of Roman triumphal art but here are imbued with specific political and theological significance.

For instance, the depiction of Victoria, the goddess of victory, writing on a shield can be interpreted as an allegory for the writing of history under Constantine’s victorious rule. 

In the same way, the Christian symbols were subtly integrated into the arch, which heralded the growing influence of the new faith under Constantine.

Figures such as Sol Invictus, the sun god, were still featured to appease traditionalists, yet the new Christian context was unmistakable.

The monument’s design reflects this shift; it incorporates both traditional Roman iconography and subtle Christian symbols.