HistoryData
war312

4th-century battle for control of Rome

October 29, 0312

Constantine's victory over Maxentius ended the Tetrarchy and is linked to his conversion to Christianity, reshaping the Roman Empire's religious course.

Quick Facts

Year
312
Category
war

Key Facts

Date
28 October AD 312
Battle site
Milvian Bridge over the Tiber River
Outcome for Maxentius
Drowned in the Tiber; body decapitated
Religious symbol used
Chi Rho painted on soldiers' shields
Commemorative monument
Arch of Constantine erected after victory

Location

Map of Rome, ItalyMap of Rome, ItalyRome, Italy

Cause → Event → Consequence

Cause

The Roman Empire was governed by the Tetrarchy, a system of multiple co-emperors. Constantine and Maxentius were rival emperors contending for dominance. Constantine marched on Rome in 312 to challenge Maxentius directly, leading both forces to converge at the strategically vital Milvian Bridge crossing on the Tiber.

Event

On 28 October 312, Constantine's army met Maxentius's forces at the Milvian Bridge. According to Christian chroniclers, Constantine's troops bore the Chi Rho symbol after a divine vision. Constantine won the engagement decisively; Maxentius attempted to retreat across the Tiber, drowned in the river, and his decapitated head was subsequently paraded through Rome.

Consequence

Constantine's victory made him master of the western Roman Empire and set him on the path to becoming sole ruler, ending the Tetrarchy. The battle is also regarded as the beginning of his conversion to Christianity, a shift with profound consequences for the religion's spread and eventual dominance throughout the Roman Empire and beyond.

Belligerents & Mobilization Analysis

Side A

1 belligerent

Constantine I
Key Commanders

Constantine I.

Side B

1 belligerent

Maxentius
Key Commanders

Maxentius.

Outcome
Decisive victory for Constantine I; Maxentius drowned and Rome fell under Constantine's control

Timeline Context

Timeline around 312312309310311313314315312 battle at Augusta Taurinorum that was won by Constantine the Great312 AD battle in the Civil Wars of the Tetrarchybattle-of-the-milvian-bridge-312