Arcus Constantini (Arch of Constantine)

The Arch of Constantine is a monumental triumphal arch built in Rome between 312 and 315 CE. Emperor Constantine dedicated it to his victory over his rival and co-emperor Maxentius following the Battle of the Milvian Bridge in 312 CE, which was fought just outside the city. The arch stands in the valley of the Colosseum, along the traditional route used for Roman triumphal processions. Unlike most Roman triumphal monuments, which celebrated victories over foreign enemies, the Arch of Constantine is distinctive because it commemorates a victory in a Roman civil war.

At 21 meters high, 25 meters wide, and 7 meters deep, the Arch of Constantine is the largest surviving Roman triumphal arch. An inscription on the monument explains its purpose.

To the Emperor Caesar Flavius Constantine, the greatest, pious, and blessed Augustus: inspired by 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.

By presenting Maxentius as a tyrant, the inscription justifies Constantine’s civil war victory as an act of liberation rather than rebellion.

The arch was carefully designed to legitimize Constantine’s rule through political and religious symbolism. One of the most important strategies was the extensive use of spolia, the reuse of sculptural elements taken from earlier imperial monuments. By incorporating reliefs originally created for respected emperors such as Trajan, Hadrian, and Marcus Aurelius, Constantine visually aligned himself with Rome’s most admired rulers and emphasized continuity with the imperial past.

Reliefs taken from a Trajanic monument celebrating the Dacian Wars show scenes of battle and victory, highlighting Constantine’s military strength and suggesting divine favor. Other panels came from a now-lost triumphal arch of Marcus Aurelius, known only through ancient texts. These reliefs depict imperial duties such as addressing troops and distributing gifts, presenting Constantine as a just, generous, and responsible ruler. Some scholars also suggest that the friezes traditionally called “Constantinian” may have originated in an earlier monument from the reign of Diocletian and were later adapted for the arch.

The Hadrianic roundels, or circular medallions, were also altered to promote Constantine and his co-ruler Licinius. In these reliefs, the faces of earlier emperors were re-carved to resemble the new rulers, reinforcing their authority and shared leadership. Several figures wear a radiate crown, an attribute associated with Sol, the Roman sun god. This symbol had been used by earlier emperors, including Augustus and Nero, to express divine favor and imperial legitimacy.

The location of the Arch of Constantine further strengthened its symbolism. It was deliberately placed near the Colosseum and the colossal statue of Sol (originally the Colossus of Nero). From certain viewpoints, the arch was positioned to visually frame the massive statue, which stood approximately 30 meters (100 feet) tall. This careful alignment reinforced Constantine’s association with Sol Invictus and connected his rule to divine protection and cosmic authority.

Bibliography:

• Grout, James. “Arch of Constantine.” University of Chicago. https://penelope.uchicago.edu/encyclopaedia_romana/romanurbs/archconstantine.html
• Hendrix, David. (2016). “Arch of Constantine.” The Byzantine Legacy. https://www.thebyzantinelegacy.com/constantine-arch
• Marlowe, E. (2006). “Framing the Sun: The Arch of Constantine and the Roman Cityscape.” The Art Bulletin, 88(2), 223–242. https://doi.org/10.1080/00043079.2006.10786288
• Platner, Samuel. (1929). “Arcus Constantini.” In A Topographical Dictionary of Ancient Rome (p.36-38). Retrieved from: https://penelope.uchicago.edu/Thayer/E/Gazetteer/Places/Europe/Italy/Lazio/Roma/Rome/_Texts/PLATOP*/Arcus_Constantini.html
• Rose, C.B. (2021). “Reconsidering the frieze on the Arch of Constantine.” Journal of Roman Archaeology 34(1), 175-210. https://doi.org/10.1017/s1047759421000015

Arcus Constantini: erected by the senate in honour of Constantine to commemorate his victory over Maxentius in 312 A.D., as the inscription in the attic records.