The victory of Constantine at the Milvian Bridge is of the greatest importance not only in the history of the Roman Empire but also for all of that Empire's heirs, including ourselves. His prophecy of the previous evening: Hoc Singo Victor Eris (in this sign ye shall conquer -- referring to the sign of Christ) proved accurate and ushered in the acceptance of Christianity as the state religion of Rome. This battle is part of a tapestry of the constant warring between the claimants of the later Tetrarchy.

     In many ways Constantine was the perfect man for the job. The son of a military man and the daughter of an innkeeper, he had a foot in both classes. Son of a repudiated mother (Constantius married Theodora, step-daughter of Maximianus, as part of an alliance arrangement) yet chosen as his father's chief assistant, capable both of bold action and of great patience, he showed time and again that he was not a safe man to oppose.

Æ Follis of Constantine I from Trier. RIC.342 . Lot. 347.

     Upon the death of Galerius in 311 AD, Constantine responded to the taunting of Maxentius by invading Italy to consolidate control of the Western Empire. Although Constantine had a formidable army of 90,000 foot and 8,000 horse1 he left about half the foot soldiers behind in Gaul to defend the Rhine border. With about 35,000 foot and 5,000 horseman, Constantine began his march over the Alps. Constantine choose the road of the Cottian Alps by Mount Cenis2 and moved with such speed that he was at the City of Susa (Segusio), which guarded the Italian side of the Alpine passes, before word had reached Maxentius that his army had left the Rhineland frontier.

     The city of Susa was a walled fortress with adequate garrison to withstand barbarian attacks. Constantine knew he had little time for a conventional siege and decided to take the city by storm. He started his assault by setting the gates ablaze with Greek Fire and following over the walls with a mass of infantry. By evening, the city had fallen and the fire was put out. Following the conquest, Constantine began a policy of forgiveness to his conquered cities forbidding plundering and the mistreatment of citizens. This policy allowed him to gain re-enforcements and supplies from the Italians tired of the heavy-handed rule of Maxentius. Meanwhile, the first true test of the campaign was being assembled in the body of a sizable heavy cavalry contingent waiting to do battle in the plains of Turin (Taurinorium) about 40 miles from Susa.

     Constantine completed his crossing of the Alps and advanced to engage Maxentius' army at Turin. Maxentius' commanders had drawn the heavy cavalry into a chose-packed wedge designed to spilt the forces of Constantine in two parts and trample his lighter troops. However, Constantine had other ideas. He recognized the advantages of mobility and although his infantry ranks were split by the cavalry charge, they did not break. He kept his infantry in a deep skirmish order, all the time raining death with missile weapons and well timed counter assaults by light cavalry and infantry clubbing riders from their mounts. Maxentius' troops fled in confusion unable to bring their numbers to effectively bear on the enemy. The retreat turned into a rout when the city of Turin closed it gates against Maxentius' fleeing army. Few of Maxentius' elite heavy horseman escaped Constantine. Constantine entered the palace of Milan (Mediolanum) victorious and all the cities of Northwest Italy soon recognized his supremacy.

     From Milan, Constantine had direct 400-mile march to Rome down the Via Aemilia to Ariminum, then down the Via Flaminia direct to Rome. But Constantine realized that if he ignored Ruricus Pompaeianus' command of the city of Verona and its nearby army, he could be caught in a pincer attack as he advanced towards the capital. Constantine decided to neutralize this threat.

     As Constantine approached, Pompaeianus detached a large portion of his cavalry which met meet him near the city of Brascia. The detachment was defeated and chased into the city of Verona where they rejoined their commander. Verona was protected from assault on three sides by the fast-flowing Adidge river which opened up to the province of Ventia to the northeast. A narrow peninsula to the west was the only normal means of approach. A siege of the city was impossible because on the open supply lines to provisions from Ventia. At length, Constantine found a passable ford over the river and approached the city from two sides cutting the city's supply and starting an effective siege After fierce resistance from the city failed to dislodge Constantine, Pompaeianus escaped during the night and raised another field army to break the siege. Although outnumbered, Constantine again defeated the Italians using superior mobility and the maneuverability possible with veteran troops under exceptional command during a pitched night battle. When the sun rose and illuminated the battlefield littered with the bodies of thousands of Italians, the city surrendered.

Æ Follis of Maxentius from Ostia. RIC.54. Lot 343

     Meanwhile, Maxentius was busy enjoying the pleasures of Rome and attempting to conceal his defeats from the populace of the city. Somehow he felt confident that he could withstand a siege of Rome as he had done before against Severus and Galerius using subornation. Eventually, his generals were able to convince him of the severity of the pending attack and the need to consolidate his forces and strike pre-emptively. A third army was raised of nearly 170,000 men, strong on paper but largely composed of older veterans softened by the luxury of the baths and entertainment's of Rome and new recruits not yet adequately trained for battle. The army was led by the elite Praetorian Guard unit that was well motivated for the battle3. It was Maxentius' first intention to personally stay in the safety of the capital while his generals fought the battle. Later, pubic opinion forced his personal action and raised concerns about his safety if he remained in the city without his guards.4

     Maxentius had recently upgraded the defenses of Rome to prepare for its defense. He strengthened the city walls and augmented the Milvian bridge over the Tiber River for better troop movement by constructing a temporary wooden bridge nearby made of boats/pontoons covered with planking and with a removable drawbridge section to be used in its defense.

Æ Centenionalis of Constantius II from Siscia. Reverse: Constantine standing holding labarum inscribed with a Christogram, crowned by Victory "Hoc Signo Victor Eris" (in this sign ye shall conquer). RIC.301. Lot. 361     

     On the eve of the battle, Constantine was visited by an Angel while he slept which showed him a Christogram (the first two letters of "Christ" in Greek - Chi, Rho) and spoke "Hoc Signo Victor Eris" (in this sign ye shall conquer). Based on this revelation (or perhaps as a political expedience) Constantine had his Army take up this symbol, placing it on the standard and painting it on the shields of the soldiers. Constantine prepared to lead the Empire's first Christian army into battle.

     On October 28, 312 AD, nine miles from Rome, Constantine's scouts reported that the Army of Maxentius was marching in a long column towards the village of Saxa Rubra on the Via Flaminian. Magnentius took up a hasty defense on lower ground with his rear defended by the Tiber river (but leaving his only lines of retreat the Milvain Bridge). Both commanders arranged their troops with a center of infantry and two flank wings of cavalry. At first, Constantine let his middle ranks sag to suck in the attacking center. In the second phase of the attack he led a charge of his Gaullish light cavalry which crushed the crushed the Moorish cavalry on the right while his counterparts dispersed the Maxentius' heavy cuirassiers on the left flank and threatened to encircle the center. The rank-and-file troops broke and fled unwilling to die for a "tyrant they had always hated and no longer feared"5.

     Maxentius ordered a retreat over the Milvain Bridge back to the safety of the walls of Rome. But, Constantine followed the retreat closely with his light cavalry and the retreat quickly turned into a mindless rout. The trained Praetorian guards refused to surrender but were unable to contain their troops or stop Constantine unfettered advances. Most of the elite guard unit died in the battle which lasted into the night.

     Maxentius' main army pressed onto the Milvain bridge and the pontoon bridge with the Army of Constantine on there heals. The shear press of the fleeing Army caused many to fall off the bridge and collapsed the drawbridge on the pontoon bridge. Maxentius fell off the bridge and was pulled to his death by the weight of his armor.

     Constantine marched into Rome victorious and was accepted as master of the Western Empire. Constantine executed Maxentius' two sons and abolished the Praetorian guards, but when the crowd asked for more blood, he refused. He was honored with a triumphal arch (still standing in Rome today) but because of the lack of competent stone cutters, it used figures borrowed from other monuments. Constantine oversaw the construction of Christian churches built in the shape of a cross and he restored property to the Church previously confiscated.

     Constantine took a personal hand in the establishment of Christianity as the state religion. In the Edit of Milan in 312, Constantine convinced his co-Emperor Licinius to shift from the neutral stance of the Edict of Tolerance, reluctantly granted by Galerius in 311 AD, to a policy of support and legal recognition for Christianity. He continued to shape the religion by presiding over the Council of Nicaea which developed the Nicene Creed, agreed upon by all factions, leading way to a universal church for his united Empire. Constantine, himself, waited until he was on his death bed to be baptized in 337 AD.

     The victory at Milvain Bridge was the first step which would eventually see Constantine defeat Licinius and become master of the whole Roman Empire. His influence over the Empire was profound, the dynasty he founded would last for 50 years and the new capital at the renamed city of Constantinople which he established in 324 AD remained the seat of power for 1100 years.

Further Reading:

Gibbon, Edward, The Decline and Fall of the Roman Empire , Modern Library, NY.

Eusebius, The History of the Church, (writing ca. 330 AD) Translated by Williamson, Dorset, 1965

Route of Constantine to Milvian Bridge

1. Zosimus, Histories written ca. 450 AD
2. There is some debate whether Constantine used the pass of Mt. Genevre or Mt. Cenis. Refer to Gibbons, The Decline and Fall of the Roman Empire" for further discussion
3. Maxentius had defied the order to reduce the size of the praetorian guard unit following the Council of Carnuntum in 308. The siege of Galerius was in part because of Maxentius inaction upon this direction. Meanwhile Constantine had reorganized his forces to de-emphasize the Praetorian Guard. The Guard could expect to lose its special privileges under Constantine.
4. See Eusebius for more details
5. Gibbon. The Decline and Fall of the Roman Empire, pg.365.