The Arch of Constantine was erected to commemorate Constantine I’s victory over Maxentius at the Milvian Bridge that took place on 28 October 312.
The Battle took its name from the Milvian Bridge, an important route over the Tiber. Constantine won the battle and started on the path that led him to end the Tetrarchy and become the sole ruler of the Roman Empire. Maxentius drowned in the Tiber during the battle; his body was later taken from the river and decapitated, his head paraded through the streets of Rome on the day following the battle.
According to chroniclers such as Eusebius of Caesarea and Lactantius, the battle marked the beginning of Constantine’s conversion to Christianity. Eusebius of Caesarea recounts that Constantine and his soldiers had a vision sent by the Christian God. This was interpreted as a promise of victory if the sign of the Chi-Rho, the first two letters of Christ‘s name in Greek, was painted on the soldiers’ shields. The Arch of Constantine, erected in celebration of the victory, certainly attributes Constantine’s success to divine intervention; however, the monument does not display any overtly Christian symbolism.
Though dedicated to Constantine, much of the decorative material incorporated earlier work from the time of the emperors Trajan, Hadrian and Marcus Aurelius, and is thus a collage. The last of the existing triumphal arches in Rome, it is also the only one to make extensive use of spolia, reusing several major reliefs from 2nd century imperial monuments, which give a striking and famous stylistic contrast to the sculpture newly created for the arch.
Whatever the faults of Maxentius, his reputation in Rome was influenced by his contributions to public building. By the time of his accession in 306 Rome was becoming increasingly irrelevant to the governance of the empire, most emperors choosing to live elsewhere and focusing on defending the fragile boundaries, where they frequently founded new cities. This factor contributed to his ability to seize power. By contrast Maxentius concentrated on restoring the capital, his epithet being conservator urbis suae (preserver of his city). Thus Constantine was perceived amongst other things as the deposer of one of the city’s greatest benefactors, and needed to acquire legitimacy. Much controversy has surrounded the patronage of the public works of this period. The German philosopher, Walter Benjamin observed that history is seen through the eyes of the victor, and Constantine and his biographers were no exception. Issuing a damnatio memoriae he set out to systematically erase the memory of Maxentius. Consequently, there remains considerable uncertainty regarding the patronage of early fourth century public buildings, including the Arch of Constantine, which may originally have been an Arch of Maxentius.