Summary
Highlights
In 312 AD, Constantine the Great invaded Italy, surprising the forces of Emperor Maxentius. His initial target was Segusio (modern Susa), which he quickly captured after its refusal to surrender. Constantine's swift and brutal advance marked the beginning of his campaign for supremacy in the Roman Empire.
Maxentius, initially popular for blocking imperial taxes and focusing on Rome, faced increasing unrest due to financial strains and a revolt in Africa. His control over Italy and North Africa was challenged as his initial promises wore thin, forcing him to reintroduce the very policies he had opposed. The Roman Empire at this time was fractured, with four Augusti vying for power.
Constantine, demonstrating restraint and aiming to be seen as a liberator, pardoned the citizens of Segusio. He then advanced, skillfully defeating a Maxentian army at Augusta Taurinorum (Turin) and occupying Mediolanum (Milan) without resistance. He continued his march to Verona, where he faced the formidable general Pompeianus.
Constantine besieged Verona, a stronghold of Maxentius's forces. After initial difficulties, Constantine faced Pompeianus, who returned with reinforcements. In a decisive night battle, Constantine's forces defeated Pompeianus, who was killed in action. This victory secured northern Italy for Constantine, paving his way towards Rome.
Constantine marched towards Rome, likely facing resistance in the Apennine passes. Maxentius's Moorish cavalry harassed Constantine's columns. At Saxa Rubra, Constantine's vanguard suffered a significant setback in an ambush, marking Maxentius's first victory against Constantine's forces in Italy. This fueled Maxentius's confidence.
Despite the victory at Saxa Rubra, Maxentius faced growing unrest in Rome. Consulting the Sibylline Books, he prophesied the demise of an 'enemy of Rome' on October 28th, his accession day, believing it referred to Constantine. Meanwhile, Constantine, encamped north of Rome, experienced a transformative vision of a Christian cross in the sky and a dream, leading him to emblazon his soldiers' shields with the Chi Rho symbol, believing he had divine support.
Maxentius positioned his army on the plain of Tor di Quinto, north of the Milvian Bridge, choosing a defensive location to negate Constantine's tactical prowess. Both armies, though with differing compositions, were formidable. Constantine's smaller but highly experienced veteran army, including units from Britain and the Rhine, were contrasted with Maxentius's larger force, which included Praetorians, veteran legionaries, but also less experienced Italian and African levies. Cavalry played a more prominent role than in earlier Roman armies.
Maxentius destroyed the pontoon bridge behind his forces, committing his army to a decisive fight. Constantine initiated the battle, leading his cavalry to overwhelm Maxentius's right wing. The ensuing chaos in Maxentius's lines and the fierce infantry clash marked a brutal contest. Despite the strength of Maxentius's Praetorians and imperial horse guard, Constantine's divinely inspired cavalry eventually broke Maxentius's second division. Maxentius fled, his army unraveling.
As Maxentius's army routed, many fled towards the Milvian Bridge, creating a deadly bottleneck where thousands drowned in the swollen Tiber. Maxentius himself, attempting to ford the river on horseback, drowned due to his heavy armor. His body was later recovered and beheaded, a symbol of Constantine's triumph.
Constantine entered Rome in triumph, prominently displaying the Chi Rho symbol. He was declared Maximus Augustus, repurposed Maxentius's construction projects, and crucially, disbanded the Praetorian Guard and imperial horse guards, replacing their camps with churches. This victory gave Constantine control of the Western Empire, and his belief that the Christian God guided his success led him to actively promote Christianity, transforming it from a persecuted religion into a dominant force with global historical consequences.