Arch of Constantine

Constantine defeated Maxentius, then the reigning emperor, at the Battle of the Milvian Bridge on 28 October 312, and entered Rome the following day amid great rejoicing. The Senate commissioned the arch then, to commemorate that victory and ten years of Constantine's reign, and construction ran from 312 to 315; the monument was dedicated by the Senate and officially opened on 25 July 315, during the decennalia, the games held every ten years, at which prayers were said and vows renewed. Constantine himself left Rome within two months of his entry and did not come back until 326. The arch has been called the first architectural work of the empire to celebrate a victory won by one Roman over another.

It was set between the Palatine and the Caelian hills, astride the ancient route of Roman triumphs where that road diverged from the Via Sacra. The triumphal procession began in the Campus Martius, passed through the Circus Maximus and around the Palatine, and immediately beyond the arch turned at the Meta Sudans for the Forum and the Capitoline. Jones argues that the arch's placement in relation to the Circus Maximus, the Temple of Venus and Rome and the base of the Colossus points to a deliberate piece of Constantinian town planning rather than the reuse of an earlier arch on the spot. Marlowe, examining the sightlines of the Colosseum valley, notes that the arch was built not over the road but a little to the north of it and shifted about two metres to the east, which hid the tall cone of the Meta Sudans fountain almost entirely behind the second pier and framed instead the colossal bronze statue of the sun god Sol, since lost. Ancient writers say almost nothing about the arch, as they say almost nothing about the Arch of Titus, so most of what is known comes from the long dedication inscription repeated on each main face of the attic. It is the largest Roman triumphal arch, 21 metres high, and one of three to survive in Rome, with the arches of Titus and of Septimius Severus.

The main inscription stood in bronze letters, and though the letters are gone the recesses that held them and their fixing holes leave it easily read. It records that the Senate and People of Rome dedicated the arch, decorated with triumphs, to the Emperor Caesar Flavius Constantinus because he, inspired by the divine and by the greatness of his mind, had delivered the state from the tyrant and all his faction at one stroke, with his army and by just force of arms. As was customary the defeated enemy is not named but called only the tyrant, which with the language of a just war served to justify a civil war against Maxentius. Two short inscriptions inside the central archway carry the same message, naming Constantine liberator of the city and founder of peace, while over the small archways the vows for the tenth and twentieth anniversaries of the reign date the monument to the decennalia he celebrated in Rome in the summer of 315.

The phrase instinctu divinitatis, inspired by the divine, has drawn long argument. Christian tradition, in Lactantius and in Eusebius of Caesarea, tells of a vision granted to Constantine during the campaign and of victory won at the Milvian Bridge under the sign of the cross. Yet official issues, coins above all, still gave prominence to the Sun god until 324, while Constantine supported the Christian church from 312; he confirmed freedom of worship across the empire in 313 and only in 325 presided over the Council of Nicaea, which he had summoned. The vague wording reads as a deliberate ambiguity, acceptable to pagan and Christian alike, and the sculpture kept that balance: scenes of sacrifice to pagan gods appear on the arch, but among the panels reused from a monument of the age of Marcus Aurelius those showing the triumph and the Capitoline sacrifice, the highest ceremony of the pagan state religion, were left out and are now in the Capitoline Museums.

By the time Maxentius came to power in 306, Rome was becoming steadily less important to the governance of the empire, most emperors preferring to live elsewhere and to defend the fragile frontiers, and those conditions helped him seize power. Unlike his predecessors he concentrated on restoring the capital, and took the epithet conservator urbis suae, preserver of his own city. Constantine was therefore seen as the man who had deposed one of Rome's great benefactors, and needed legitimacy. He issued a damnatio memoriae and set out to erase the memory of Maxentius systematically, which is why the patronage of Roman public building in the early fourth century remains so uncertain, the arch included: it may have begun as an arch of Maxentius.

Other origins have been proposed. Excavations in the arch's foundations on one side prompted the argument that the monument was built under Hadrian and heavily reworked in Constantine's time, with the columns moved outward, the whole attic rebuilt, the Great Trajanic Frieze set into the walls of the central passage and Constantinian carving either cut into blocks already in the masonry or inserted new; on that reading the Hadrianic roundels belong to the original decoration. One scholar put the first building as early as the reign of Domitian, from 81 to 96. Recent work treats the monument chiefly as a commission of the Senate, initiated by it and framed to suit Constantine's political image, and some recent historiography suggests that the influential model advanced by L'Orange and von Gerkan in 1939 may itself have been shaped by the Fascist climate of 1930s Rome, when Mussolini pressed visual links between the ancient city and the modern one. Much of the sculpture came from earlier monuments to Trajan, Hadrian and Marcus Aurelius, with the portrait heads recut as Constantine's.

In the Middle Ages the arch was built into one of the family strongholds of the city. In 1530 Lorenzino de' Medici was driven out of Rome for cutting the heads off the arch's reliefs for his own amusement; they were partly replaced in the 18th century, when restoration work was first carried out on the monument. The most recent excavations were made in the late 1990s, shortly before the Great Jubilee of 2000.

At the Rome Olympics of 1960 the arch served as the finish of the marathon, won barefoot by the Ethiopian Abebe Bikila. It stands today under Italian national heritage protection, and was damaged by a direct lightning strike on 3 September 2024.