Battle at the Milvian Bridge Data
Date: October 28, 312
Location: Near the city of Rome; Milvian Bridge over the Tiber River
The Tetrarchy Led to Conflict
Six years before the famous Roman civil war battle at the Milvian Bridge, Constantine had succeeded his father Constantius as emperor, by acclaim of his father's troops. This was near the start of the monarchical period of the Roman Empire, the Dominate, which began with Emperor Diocletian (no longer just princeps, signifying 'first among equals,' but now known as dominus 'lord') who identified with the king of the gods. It was Diocletian who established the four-part rule of the Roman Empire, known as the tetrarchy, in 285, and then subsequently failed to iron out all the kinks. By this tetrarchical arrangement, there were two senior emperors and two non-hereditary juniors, each in charge of roughly a quadrant of the Roman Empire. The senior emperors had been Diocletian, in the East, and Maximian (father of Maxentius), who had control of northern provinces, Italy, Africa, and Spain. Constantine's father Constantius became Maxentius' junior and put in charge of Gaul and Britain. Diocletian's junior was Galerius, who controlled the Balkans. When Diocletian and Maximian abdicated (to give up the throne was Diocletian's idea, not Maximian's), Constantius and Galerius became the senior emperors. The new juniors were Flavius Valerius Severus and C. Galerius Valerius Maximinus Daia. Note: No Constantine.
The plan was for the juniors to take the place of the seniors and then appoint juniors in their places, but Constantine had not been one of the juniors at the time of his father's death when he had assumed the purple. The rulers reached a compromise: Constantine became the junior with Severus his senior. Although the assignment of power was not hereditary -- even though Constantine had come to power following his father's death -- Maximian's son Maxentius also wanted power. In his bid to gain it, he drove out Severus. Instead of letting Maximian take over, senior emperor Galerius appointed his friend Valerius Licinianus Licinius (r. 308 to 324) to fill Severus' position. (When Galerius died, Daia and Licinius split up his part of the empire.) Meanwhile, Maximian and his son Maxentius had assumed power in Italy, controlling Africa, Sardinia, and Corsica, as well. Galerius failed in his inevitable bid to squash Maxentius.
Constantine Fights Maxentius
Constantine took over. To invade the domain of Maxentius, Constantine raised an army from Britain, and also manned by Germans and Celts, which Zosimus says amounted to 90,000 foot soldiers and 8000 cavalry. At the time, Maxentius raised his amy of 170,000 foot soldiers and 18,000 foot soldiers. (The figures given for ancient wars tend to be inflated, but give an estimation of relative strength.)
Constantine defeated Maxentius in battles at Turin and Verona, and then went South towards Rome.
The Sign of the Cross Changes World History
Lactantius implies that it was on the last day of his march towards Rome that the sign* of the cross appeared to Constantine and his army and provided the vision of Christ telling him to put the mark on the shields and promised victory.
* Constantine (1) received a sign or (2) had a dream or (3) heard a voice telling him to put his faith in Christ."Accordingly he called on him with earnest prayer and supplications that he would reveal to him who he was, and stretch forth his right hand to help him in his present difficulties. And while he was thus praying with fervent entreaty, a most marvelous sign appeared to him from heaven, the account of which it might have been hard to believe had it been related by any other person. But since the victorious emperor himself long afterwards declared it to the writer of this history, when he was honored with his acquaintance and society, and confirmed his statement by an oath, who could hesitate to accredit the relation, especially since the testimony of after-time has established its truth? He said that about noon, when the day was already beginning to decline, he saw with his own eyes the trophy of a cross of light in the heavens, above the sun, and bearing the inscription, CONQUER BY THIS. At this sight he himself was struck with amazement, and his whole army also, which followed him on this expedition, and witnessed the miracle.
He said, moreover, that he doubted within himself what the import of this apparition could be. And while he continued to ponder and reason on its meaning, night suddenly came on ; then in his sleep the Christ of God appeared to him with the same sign which he had seen in the heavens, and commanded him to make a likeness of that sign which he had seen in the heavens, and to use it as a safeguard in all engagements with his enemies."
Eusebius on Constantine's Vision at the Milvian Bridge
Maxentius Dies Amid His Fleeing Men
When Constantine was near the Flaminian Way, Maxentius sent out forces to meet him. His officers went out the Flaminian Gate and crossed the Milvian Bridge.
The day of battle, Constantine took the initiative, leading his Gallic cavalry. It should be noted that Maxentius was unpopular and is portrayed as a tyrant, while Constantine is depicted as well liked by his men. Attacked, the cavalry of Maxentius gave way. Then the Italian infantry fled. Maxentius' loyal and capable Praetorians held out, but were slain. Speidel comments that when the Praetorian fell, Rome ceased to be the capital of the Empire.
The Milvian Bridge broke under the fleeing men in Maxentius' army. Maxentius, decked out in heavy armor, fell into the water and drowned.
Zosimus Describes the Battle at the Milvian Bridge
Zosimus describes the events of the fateful day:
"Both being thus prepared, Maxentius threw a bridge over the Tiber, which was not of one entire piece, but divided into two parts, the centre of the bridge being made to fasten with irons, which might be drawn out upon occasion. He gave orders to the workmen, that as soon as they saw the army of Constantine upon the juncture of the bridge, they should draw out the iron, fastenings, that the enemy who stood upon it might fall into the river."
"Constantine, advancing with his. army to Rome, encamped in a field before the city, which was broad and therefore convenient for cavalry. Maxentius in the mean time shut himself up within the walls, and sacrificed to the gods, and, moreover, consulted the Sibylline oracles concerning the event of the war. Finding a prediction, that whoever designed any harm to the Romans should die a miserable death, he applied it to himself, because he withstood those that came against Rome, and wished to take it. His application indeed proved just. For when Maxentius drew out his army before the city, and was marching over the bridge that he himself had constructed, an infinite number of owls flew down and covered the wall. When Constantine saw this, he ordered his men to stand to their arms. And the two armies being drawn up opposite to each other, Constantine sent his cavalry against that of the enemy, whom they charged with such impetuosity that they threw them into disorder. The signal being given to the infantry, they likewise marched in good order towards the enemy. A furious battle having commenced, the Romans themselves, and their foreign allies, were unwilling to risk their lives, as they wished for deliverance from the bitter tyranny with which they were burdened; though the other troops were slain in great numbers, being either trod to death by the horse, or killed by the foot."
"As long as the cavalry kept their ground, Maxentius retained some hopes, but when they gave way, he tied with the rest over the bridge into the city. The beams not being strong enough to bear so great a weight, they broke; and Maxentius, with the others, was carried with the stream down the river."
The End of the Praetorians
Maxentius is portrayed as a tyrant who was unpopular. His head was stuck on a pike and carried around Rome, which opened its gates to Constantine. Zosimus describes the motivation for this macabre parade:
"When the news of this victory was reported in the city, none dared to show any joy for what had happened, because many thought it was an unfounded report. But when the head of Maxentius was brought upon a spear, their fear and dejection were changed to joy and pleasure. On this occasion Constantine punished very few, and they were only some few of the nearest friends of Maxentius; but he abolished the praetorian troops, and destroyed the fortresses in which they used to reside."
- Constantine the Great: The union of the state and the church, by Edward Lewes Cutts
- Rome: its rise and fall: a text-book for high schools and colleges, by Philip Van Ness Myers
- Dictionary of Greek and Roman Geography
- The midsummer of Italian art: containing an examination of the works of Fra Angelico, Michel Angelo, Leonardo da Vinci, Raphael Santi, and Correggio, by Frank Preston Stearns (G.P. Putnam's Sons, 1895)
- Riding for Caesar: The Roman Emperors' Horse Guards, by Michael P. Speidel
- The Battle 100: The Stories Behind History's Most Influential Battles, by Michael Lee Lanning
- Rome Tour
- Conatantine at the Battle of Milvian Bridge from the About.com Guide to Military History