Constantine the Great enters Rome after his victory at the Battle of the Milvian Bridge, stages a grand adventus in the city, and is met with popular jubilation. Maxentius' body is fished out of the Tiber and beheaded.

Constantine I, also known as Constantine the Great, was a Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a pivotal role in elevating the status of Christianity in Rome, decriminalising Christian practice and ceasing Christian persecution. This was a turning point in the Christianisation of the Roman Empire. He founded the city of Constantinople and made it the capital of the Empire, which it remained for over a millennium.

The Battle of the Milvian Bridge took place between the Roman Emperors Constantine I and Maxentius on 28 October AD 312. It takes 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, and his head was paraded through the streets of Rome on the day following the battle before being sent to Africa.

In the Roman Empire during Late Antiquity, the adventus was a ceremony held to celebrate the arrival at a city of a Roman emperor or other dignitaries. The imperial adventus was the period's "ceremonial par excellence", celebrating both the emperor's arrival and the blessing of the imperial presence itself on the city's security. The term is also used to refer to artistic depictions of such ceremonies.

Marcus Aurelius Valerius Maxentius was a Roman emperor from 306 until his death in 312. Despite ruling in Italy and North Africa, and having the recognition of the Senate in Rome, he was not recognized as a legitimate emperor by his fellow emperors.