What Roman triumphal arch in Rome was built in 315 AD to commemorate Constantine's victory?

The Roman triumphal arch in Rome built in AD 315 to commemorate Constantine’s victory is the Arch of Constantine.

The Senate dedicated the arch on 25 July AD 315, marking Constantine’s victory over Maxentius at the Battle of the Milvian Bridge in 312. The monument stands beside the Colosseum and spans the Via Triumphalis, the route used by victorious Roman commanders entering the city. Its inscription presents Constantine as a restorer of the Roman state and links his success to divine inspiration.

The arch is notable for its extensive reuse of earlier sculpture. Reliefs and statues from monuments associated with Trajan, Hadrian, and Marcus Aurelius were incorporated into the structure, while scenes specifically made for Constantine occupy other sections. This mixture gives the monument a distinctive visual character and has made it important for studying late Roman artistic style.

It is often confused with the Arch of Septimius Severus, which stands in the Roman Forum, or the Arch of Titus, near the Colosseum. The Arch of Constantine is the one directly associated with Constantine’s civil war victory and his rise to sole power in the West.