Arch of Constantine

The largest surviving Roman triumphal arch (315 AD), erected by the Senate to celebrate Constantine's victory over Maxentius at the Battle of the Milvian Bridge in 312 — the moment that began the Roman Empire's transition to Christianity. The arch reuses sculpture from earlier monuments of Trajan, Hadrian, and Marcus Aurelius, a practice that reveals both political messaging (linking Constantine to the 'good emperors') and the declining sculptural skills of the late empire. Free to view, immediately beside the Colosseum.