Civil Wars of the Tetrarchy (306-324 AD)
Encyclopedia
The Civil Wars of the Tetrarchy were a series of conflicts between the co-emperors of the Roman Empire
, starting in 306
AD with the usurpation of Maxentius
and the defeat of Severus
, and ending with the defeat of Licinius
at the hands of Constantine I
in 324
AD.
refers to the administrative division of the Roman Empire instituted by Roman Emperor
Diocletian
in 293 AD, marking the end of the Crisis of the Third Century
and the recovery of the Roman Empire. The first phase, sometimes referred to as the Diarchy
('the rule of two'), involved the designation of the general Maximian
as co-emperor - firstly as Caesar
(junior emperor) in 285, followed by his promotion to Augustus in 286. Diocletian
took care of matters in the Eastern regions of the Empire while Maximian similarly took charge of the Western regions. In 293, feeling more focus was needed on both civic and military problems, Diocletian, with Maximian's consent, expanded the imperial college by appointing two Caesar
s (one responsible to each Augustus
) - Galerius
and Constantius Chlorus
.
The senior emperors jointly abdicated and retired in 305
AD, allowing Constantius and Galerius to be elevated in rank to Augusti. They in turn appointed two new Caesars - Severus
in the west under Constantius, and Maximinus
in the east under Galerius.
in 306
AD saw the first crack in the political edifice of the Tetrarchy. Rather than accepting the elevation of Severus from Caesar to Emperor, the troops at York elevated Constantius’ son, Constantine
, to the position of emperor . Contacting Galerius as the senior emperor, he requested recognition as heir to his father's throne, and passed off responsibility for his unlawful ascension on his army, claiming they had "forced it upon him". Galerius was put into a fury by the message; he almost set the portrait on fire. His advisers calmed him, and argued that outright denial of Constantine's claims would mean certain war. Galerius was compelled to compromise: he granted Constantine the title "Caesar" rather than "Augustus" (The latter office went to Severus instead). Wishing to make it clear that he alone gave Constantine legitimacy, Galerius personally sent Constantine the emperor's traditional purple robes
. Constantine accepted the decision, knowing that it would remove doubts as to his legitimacy.
This act motivated Maxentius
, the son of Maximian to also declare himself Emperor at Rome
in 306 AD. Galerius, by now fearful that others would also attempt to become emperor, ordered Severus into Italy to deal with the usurper. Severus moved from his capital, Mediolanum
, towards Rome, at the head of an army previously commanded by Maximian. Fearing the arrival of Severus, Maxentius offered Maximian the co-rule of the empire. Maximian accepted, and when Severus arrived under the walls of Rome and besieged it, his men deserted him and passed to Maximian, their old commander. Severus fled to Ravenna
, an impregnable position: Maximian offered to spare his life and treat him humanely if the latter surrendered peaceably, which he did in March or April 307. Despite Maximian's assurance, Severus was nonetheless displayed as a captive and later imprisoned at Tres Tabernae, before being eventually killed.
The joint rule of Maxentius and Maximian in Rome was tested further when Galerius himself marched to Italy in the summer of 307 with an even larger army. While negotiating with the invader, Maxentius could repeat what he did to Severus: by the promise of large sums of money, and the authority of Maximian, many soldiers of Galerius defected to him. Galerius was forced to withdraw, plundering Italy on his way. Some time during the invasion, Severus was put to death by Maxentius, probably at Tres Tabernae near Rome (the exact circumstances of his death are not certain). After the failed campaign of Galerius, Maxentius' reign over Italy and Africa was firmly established. Beginning in 307 already, he tried to arrange friendly contacts with Constantine, and in the summer of that year, Maximian travelled to Gaul
, where Constantine married his daughter Fausta
and was in turn appointed Augustus by the senior emperor. However, Constantine tried to avoid breaking with Galerius, and did not openly support Maxentius during the invasion.
In 308, probably April, Maximian tried to depose his son in an assembly of soldiers in Rome; surprisingly to him, the present troops remained faithful to his son, and he had to flee to Constantine.
In the conference of Carnuntum
in the autumn of 308, Maxentius was once again denied recognition as legitimate emperor, and Licinius
was appointed Augustus with the task of regaining the usurper's domain.
In 310, Maximian rebelled against Constantine while the emperor was on campaign against the Franks. Maximian had been sent south to Arles with part of Constantine's army to defend against attacks by Maxentius in southern Gaul. In Arles, Maximian announced that Constantine was dead and took up the imperial purple
. Despite offering bribes to any who would support him as emperor, most of Constantine's army remained loyal, and Maximian was compelled to leave. Constantine soon heard of the rebellion, abandoned his campaign against the Franks, and moved quickly to southern Gaul, where he confronted the fleeing Maximian at Massilia (Marseille
). The town was better able to withstand a longer siege than Arles, but it made little difference as loyal citizens opened the rear gates to Constantine. Maximian was captured, reproved for his crimes, and stripped of his title for the third and last time. Constantine granted Maximian some clemency but strongly encouraged his suicide. In July 310, Maximian hanged himself.
of Rome
, Eusebius
.
Maxentius' rule was nevertheless insecure. His early support dissolved in the wake of heightened tax rates and depressed trade; riots broke out in Rome and Carthage; and Domitius Alexander
was able to briefly usurp his authority in Africa. By 312, he was a man barely tolerated, not one actively supported, even among Christian Italians. In the summer of 311, Maxentius mobilized against Constantine while Licinius was occupied with affairs in the East. He declared war on Constantine, vowing to avenge his father's "murder". To prevent Maxentius from forming an alliance against him with Licinius, Constantine forged his own alliance with Licinius over the winter of 311–12, and offered him his sister Constantia in marriage. Maximin considered Constantine's arrangement with Licinius an affront to his authority. In response, he sent ambassadors to Rome, offering political recognition to Maxentius in exchange for a military support. Maxentius accepted. According to Eusebius, inter-regional travel became impossible, and there was military buildup everywhere. There was "not a place where people were not expecting the onset of hostilities every day".
Constantine's advisers and generals cautioned against preemptive attack on Maxentius; even his soothsayers recommended against it, stating that the sacrifices had produced unfavorable omens. Constantine, with a spirit that left a deep impression on his followers, inspiring some to believe that he had some form of supernatural guidance, ignored all these cautions. Early in the spring of 312, Constantine crossed the Cottian Alps
with a quarter of his army, a force numbering about 40,000. The first town his army encountered was Segusium (Susa, Italy
), a heavily fortified town that shut its gates to him. Constantine ordered his men to set fire to its gates and scale its walls. He took the town quickly. Constantine ordered his troops not to loot the town, and advanced with them into northern Italy.
At the approach to the west of the important city of Augusta Taurinorum (Turin
, Italy), Constantine encountered a large force of heavily armed Maxentian cavalry. In the ensuing battle
Constantine's army encircled Maxentius' cavalry, flanked them with his own cavalry, and dismounted them with blows from his soldiers' iron-tipped clubs. Constantine's armies emerged victorious. Turin refused to give refuge to Maxentius' retreating forces, opening its gates to Constantine instead. Other cities of the north Italian plain sent Constantine embassies of congratulation for his victory. He moved on to Milan, where he was met with open gates and jubilant rejoicing. Constantine rested his army in Milan until mid-summer 312, when he moved on to Brixia
(Brescia
).
Brescia's army was easily dispersed, and Constantine quickly advanced to Verona
, where a large Maxentian force was camped. Ruricius Pompeianus, general of the Veronese forces and Maxentius' praetorian prefect, was in a strong defensive position, since the town was surrounded on three sides by the Adige
. Constantine sent a small force north of the town in an attempt to cross the river unnoticed. Ruricius sent a large detachment to counter Constantine's expeditionary force, but was defeated. Constantine's forces successfully surrounded the town and laid siege. Ruricius gave Constantine the slip and returned with a larger force to oppose Constantine. Constantine refused to let up on the siege, and sent only a small force to oppose him. In the desperately fought encounter
that followed, Ruricius was killed and his army destroyed. Verona surrendered soon afterwards, followed by Aquileia
, Mutina (Modena
), and Ravenna
. The road to Rome was now wide open to Constantine.
Maxentius prepared for the same type of war he had waged against Severus and Galerius: he sat in Rome and prepared for a siege. He still controlled Rome's praetorian guards, was well-stocked with African grain, and was surrounded on all sides by the seemingly impregnable Aurelian Walls
. He ordered all bridges across the Tiber
cut, reportedly on the counsel of the gods, and left the rest of central Italy undefended; Constantine secured that region's support without challenge. Constantine progressed slowly along the Via Flaminia
, allowing the weakness of Maxentius to draw his regime further into turmoil. Maxentius' support continued to weaken: at chariot races on 27 October, the crowd openly taunted Maxentius, shouting that Constantine was invincible. Maxentius, no longer certain that he would emerge from a siege victorious, built a temporary boat bridge across the Tiber in preparation for a field battle against Constantine. On 28 October 312, the sixth anniversary of his reign, he approached the keepers of the Sibylline Books
for guidance. The keepers prophesied that, on that very day, "the enemy of the Romans" would die. Maxentius advanced north to meet Constantine in battle.
Maxentius organized his forces—still twice the size of Constantine's—in long lines facing the battle plain, with their backs to the river. Constantine's army arrived at the field bearing unfamiliar symbols on either its standards or its soldiers' shields. According to Lactantius, Constantine was visited by a dream the night before the battle, wherein he was advised "to mark the heavenly sign of God on the shields of his soldiers...by means of a slanted letter X with the top of its head bent round, he marked Christ on their shields." Eusebius describes another version, where, while marching at midday, "he saw with his own eyes in the heavens a trophy of the cross arising from the light of the sun, carrying the message, In Hoc Signo Vinces or "Conquer By This"; in Eusebius's account, Constantine had a dream the following night, in which Christ appeared with the same heavenly sign, and told him to make a standard, the labarum
, for his army in that form. Eusebius is vague about when and where these events took place, but it enters his narrative before the war against Maxentius begins. Eusebius describes the sign as Chi
(Χ) traversed by Rho
(Ρ), or ☧ a symbol representing the first two letters of the Greek spelling of the word Christos or Christ. The Eusebian description of the vision has been explained as a "solar halo
", a meteorological phenomenon which can produce similar effects. In 315 a medallion was issued at Ticinum showing Constantine wearing a helmet emblazoned with the Chi-Rho, and coins issued at Siscia in 317/18 repeat the image. The figure was otherwise rare, however, and is uncommon in imperial iconography and propaganda before the 320s.
Constantine deployed his own forces along the whole length of Maxentius' line. He ordered his cavalry to charge, and they broke Maxentius' cavalry. He then sent his infantry against Maxentius' infantry, pushing many into the Tiber where they were slaughtered and drowned. The battle was brief: Maxentius' troops were broken before the first charge. Maxentius' horse guards and praetorians initially held their position, but broke under the force of a Constantinian cavalry charge; they also broke ranks and fled to the river. Maxentius rode with them, and attempted to cross the bridge of boats, but he was pushed by the mass of his fleeing soldiers into the Tiber, and drowned.
Constantine entered Rome on 29 October. He staged a grand adventus
in the city, and was met with popular jubilation. Maxentius' body was fished out of the Tiber and decapitated. His head was paraded through the streets for all to see. After the ceremonies, Maxentius' disembodied head was sent to Carthage
; at this Carthage would offer no further resistance.
and Licinius
. Daia was unhappy that Licinius had been made senior emperor by Galerius, and took the first available opportunity to declare himself as emperor. Licinius held the eastern European provinces, while Daia took possession of the Asiatic provinces.
In the autumn of 312, while Constantine was fighting Maxentius, Daia was busy campaigning against the Armenians. He had returned to Syria by February 313 when discovered the alliance that had been forged by Constantine and Licinius. He in turn entered into a secret alliance with Maxentius, but was soon flustered by the death of Maxentius. Deciding to take the initiative, Daia left Syria with 70,000 men and reached Bythinia, although harsh weather he encountered along the way had gravely weakened his army. In April 313, he crossed the Bosporus
and went to Byzantium
, which was held by Licinius' troops. Undeterred, he took the town after an eleven-day siege. He moved to Heraclea, which he captured after a short siege, before moving his forces to the first posting station. With a much smaller body of men, possibly around 30,000, Licinius arrived at Adrianople while Daia was still besieging Heraclea
. On 30 April 313, the two armies clashed at the Battle of Tzirallum
, and in the ensuing battle Daia's forces were crushed. Ridding himself of the imperial purple and dressing like a slave, Daia fled to Nicomedia
. Believing he still had a chance to come out victorious, Daia attempted to stop the advance of Licinius at the Cilician Gates
by establishing fortifications there. Unfortuately for Daia, Licinius' army succeeded in breaking through, forcing Daia to retreat to Tarsus where Licinius continued to press him on land and sea. The war between them only ended with Daia’s death in August 313.
After Maxentius’ defeat, Constantine gradually consolidated his military superiority over his rivals in the crumbling Tetrarchy. In 313, he met Licinius
in Milan
to secure their alliance by the marriage of Licinius and Constantine's half-sister Constantia
. During this meeting, the emperors agreed on the so-called Edict of Milan
, officially granting full tolerance to "Christianity and all" religions in the Empire. The document had special benefits for Christians, legalizing their religion and granting them restoration for all property seized during Diocletian's persecution. It repudiates past methods of religious coercion and used only general terms to refer to the divine sphere — "Divinity" and "Supreme Divinity", summa divinitas. The conference was cut short, however, when news reached Licinius that his rival Maximin had crossed the Bosporus
and invaded European territory. Licinius departed and eventually defeated Maximinus, gaining control over the entire eastern half of the Roman Empire. Relations between the two remaining emperors deteriorated, though, and either in 314 or 316, Constantine and Licinius fought against one another in the war of Cibalae
, with Constantine being victorious. They clashed again in the Battle of Campus Ardiensis
in 317, and agreed to a settlement in which Constantine's sons Crispus
and Constantine II
, and Licinius' son Licinianus were made caesars
.
In the year 320, Licinius
reneged on the religious freedom promised by the Edict of Milan
in 313 and began to oppress Christians anew. It became a challenge to Constantine in the west, climaxing in the great civil war of 324. Licinius, aided by Goth
mercenaries
, represented the past and the ancient Pagan
faiths. Constantine and his Franks
marched under the standard of the labarum
, and both sides saw the battle in religious terms. Supposedly outnumbered, but fired by their zeal, Constantine's army emerged victorious in the Battle of Adrianople
. Licinius fled across the Bosphorus and appointed Martius Martinianus, the commander of his bodyguard, as Caesar, but Constantine next won the Battle of the Hellespont
, and finally the Battle of Chrysopolis
on 18 September 324. Licinius and Martinianus surrendered to Constantine at Nicomedia on the promise their lives would be spared: they were sent to live as private citizens in Thessalonica and Cappadocia respectively, but in 325 Constantine accused Licinius of plotting against him and had them both arrested and hanged; Licinius's son (the son of Constantine's half-sister) was also eradicated. Thus Constantine became the sole emperor of the Roman Empire, ending the Civil Wars of the Tetrarchy.
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....
, starting in 306
306
Year 306 was a common year starting on Tuesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and Valerius...
AD with the usurpation of Maxentius
Maxentius
Maxentius was a Roman Emperor from 306 to 312. He was the son of former Emperor Maximian, and the son-in-law of Emperor Galerius.-Birth and early life:Maxentius' exact date of birth is unknown; it was probably around 278...
and the defeat of Severus
Flavius Valerius Severus
Severus , sometimes known as Severus II, was a Western Roman Emperor from 306 to 307.- Officer in the Roman army :Severus was of humble birth, born in the Illyrian provinces around the middle of the third century AD...
, and ending with the defeat of Licinius
Licinius
Licinius I , was Roman Emperor from 308 to 324. Co-author of the Edict of Milan that granted official toleration to Christians in the Roman Empire, for the majority of his reign he was the rival of Constantine I...
at the hands of Constantine I
Constantine I
Constantine the Great , also known as Constantine I or Saint Constantine, was Roman Emperor from 306 to 337. Well known for being the first Roman emperor to convert to Christianity, Constantine and co-Emperor Licinius issued the Edict of Milan in 313, which proclaimed religious tolerance of all...
in 324
324
Year 324 was a leap year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Crispus and Constantinus...
AD.
Background
The TetrarchyTetrarchy
The term Tetrarchy describes any system of government where power is divided among four individuals, but usually refers to the tetrarchy instituted by Roman Emperor Diocletian in 293, marking the end of the Crisis of the Third Century and the recovery of the Roman Empire...
refers to the administrative division of the Roman Empire instituted by Roman Emperor
Roman Emperor
The Roman emperor was the ruler of the Roman State during the imperial period . The Romans had no single term for the office although at any given time, a given title was associated with the emperor...
Diocletian
Diocletian
Diocletian |latinized]] upon his accession to Diocletian . c. 22 December 244 – 3 December 311), was a Roman Emperor from 284 to 305....
in 293 AD, marking the end of the Crisis of the Third Century
Crisis of the Third Century
The Crisis of the Third Century was a period in which the Roman Empire nearly collapsed under the combined pressures of invasion, civil war, plague, and economic depression...
and the recovery of the Roman Empire. The first phase, sometimes referred to as the Diarchy
Diarchy
Diarchy , from the Greek δι- "twice" and αρχια, "rule", is a form of government in which two individuals, the diarchs, are the heads of state. In most diarchies, the diarchs hold their position for life and pass the responsibilities and power of the position to their children or family when they...
('the rule of two'), involved the designation of the general Maximian
Maximian
Maximian was Roman Emperor from 286 to 305. He was Caesar from 285 to 286, then Augustus from 286 to 305. He shared the latter title with his co-emperor and superior, Diocletian, whose political brain complemented Maximian's military brawn. Maximian established his residence at Trier but spent...
as co-emperor - firstly as Caesar
Caesar (title)
Caesar is a title of imperial character. It derives from the cognomen of Julius Caesar, the Roman dictator...
(junior emperor) in 285, followed by his promotion to Augustus in 286. Diocletian
Diocletian
Diocletian |latinized]] upon his accession to Diocletian . c. 22 December 244 – 3 December 311), was a Roman Emperor from 284 to 305....
took care of matters in the Eastern regions of the Empire while Maximian similarly took charge of the Western regions. In 293, feeling more focus was needed on both civic and military problems, Diocletian, with Maximian's consent, expanded the imperial college by appointing two Caesar
Caesar (title)
Caesar is a title of imperial character. It derives from the cognomen of Julius Caesar, the Roman dictator...
s (one responsible to each Augustus
Augustus (honorific)
Augustus , Latin for "majestic," "the increaser," or "venerable", was an Ancient Roman title, which was first held by Gaius Julius Caesar Augustus , and subsequently came to be considered one of the titles of what are now known as the Roman Emperors...
) - Galerius
Galerius
Galerius , was Roman Emperor from 305 to 311. During his reign he campaigned, aided by Diocletian, against the Sassanid Empire, sacking their capital Ctesiphon in 299. He also campaigned across the Danube against the Carpi, defeating them in 297 and 300...
and Constantius Chlorus
Constantius Chlorus
Constantius I , commonly known as Constantius Chlorus, was Roman Emperor from 293 to 306. He was the father of Constantine the Great and founder of the Constantinian dynasty. As Caesar he defeated the usurper Allectus in Britain and campaigned extensively along the Rhine frontier, defeating the...
.
The senior emperors jointly abdicated and retired in 305
305
Year 305 was a common year starting on Monday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and Valerius...
AD, allowing Constantius and Galerius to be elevated in rank to Augusti. They in turn appointed two new Caesars - Severus
Flavius Valerius Severus
Severus , sometimes known as Severus II, was a Western Roman Emperor from 306 to 307.- Officer in the Roman army :Severus was of humble birth, born in the Illyrian provinces around the middle of the third century AD...
in the west under Constantius, and Maximinus
Maximinus
Maximinus II , also known as Maximinus Daia or Maximinus Daza, was Roman Emperor from 308 to 313. He was born of Dacian peasant stock to the half sister of the emperor Galerius near their family lands around Felix Romuliana; a rural area then in the Danubian region of Moesia, now Eastern Serbia.He...
in the east under Galerius.
Opening gambits
The death of Constantius at YorkYork
York is a walled city, situated at the confluence of the Rivers Ouse and Foss in North Yorkshire, England. The city has a rich heritage and has provided the backdrop to major political events throughout much of its two millennia of existence...
in 306
306
Year 306 was a common year starting on Tuesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and Valerius...
AD saw the first crack in the political edifice of the Tetrarchy. Rather than accepting the elevation of Severus from Caesar to Emperor, the troops at York elevated Constantius’ son, Constantine
Constantine I
Constantine the Great , also known as Constantine I or Saint Constantine, was Roman Emperor from 306 to 337. Well known for being the first Roman emperor to convert to Christianity, Constantine and co-Emperor Licinius issued the Edict of Milan in 313, which proclaimed religious tolerance of all...
, to the position of emperor . Contacting Galerius as the senior emperor, he requested recognition as heir to his father's throne, and passed off responsibility for his unlawful ascension on his army, claiming they had "forced it upon him". Galerius was put into a fury by the message; he almost set the portrait on fire. His advisers calmed him, and argued that outright denial of Constantine's claims would mean certain war. Galerius was compelled to compromise: he granted Constantine the title "Caesar" rather than "Augustus" (The latter office went to Severus instead). Wishing to make it clear that he alone gave Constantine legitimacy, Galerius personally sent Constantine the emperor's traditional purple robes
Tyrian purple
Tyrian purple , also known as royal purple, imperial purple or imperial dye, is a purple-red natural dye, which is extracted from sea snails, and which was possibly first produced by the ancient Phoenicians...
. Constantine accepted the decision, knowing that it would remove doubts as to his legitimacy.
This act motivated Maxentius
Maxentius
Maxentius was a Roman Emperor from 306 to 312. He was the son of former Emperor Maximian, and the son-in-law of Emperor Galerius.-Birth and early life:Maxentius' exact date of birth is unknown; it was probably around 278...
, the son of Maximian to also declare himself Emperor at Rome
Rome
Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...
in 306 AD. Galerius, by now fearful that others would also attempt to become emperor, ordered Severus into Italy to deal with the usurper. Severus moved from his capital, Mediolanum
Mediolanum
Mediolanum, the ancient Milan, was an important Celtic and then Roman centre of northern Italy. This article charts the history of the city from its settlement by the Insubres around 600 BC, through its conquest by the Romans and its development into a key centre of Western Christianity and capital...
, towards Rome, at the head of an army previously commanded by Maximian. Fearing the arrival of Severus, Maxentius offered Maximian the co-rule of the empire. Maximian accepted, and when Severus arrived under the walls of Rome and besieged it, his men deserted him and passed to Maximian, their old commander. Severus fled to Ravenna
Ravenna
Ravenna is the capital city of the Province of Ravenna in the Emilia-Romagna region of Italy and the second largest comune in Italy by land area, although, at , it is little more than half the size of the largest comune, Rome...
, an impregnable position: Maximian offered to spare his life and treat him humanely if the latter surrendered peaceably, which he did in March or April 307. Despite Maximian's assurance, Severus was nonetheless displayed as a captive and later imprisoned at Tres Tabernae, before being eventually killed.
The joint rule of Maxentius and Maximian in Rome was tested further when Galerius himself marched to Italy in the summer of 307 with an even larger army. While negotiating with the invader, Maxentius could repeat what he did to Severus: by the promise of large sums of money, and the authority of Maximian, many soldiers of Galerius defected to him. Galerius was forced to withdraw, plundering Italy on his way. Some time during the invasion, Severus was put to death by Maxentius, probably at Tres Tabernae near Rome (the exact circumstances of his death are not certain). After the failed campaign of Galerius, Maxentius' reign over Italy and Africa was firmly established. Beginning in 307 already, he tried to arrange friendly contacts with Constantine, and in the summer of that year, Maximian travelled to Gaul
Roman Gaul
Roman Gaul consisted of an area of provincial rule in the Roman Empire, in modern day France, Belgium, Luxembourg, and western Germany. Roman control of the area lasted for less than 500 years....
, where Constantine married his daughter Fausta
Fausta
Fausta Flavia Maxima was a Roman Empress, daughter of the Roman Emperor Maximianus. To seal the alliance between them for control of the Tetrarchy, in 307 Maximianus married her to Constantine I, who set aside his wife Minervina in her favour. Constantine and Fausta had been betrothed since...
and was in turn appointed Augustus by the senior emperor. However, Constantine tried to avoid breaking with Galerius, and did not openly support Maxentius during the invasion.
In 308, probably April, Maximian tried to depose his son in an assembly of soldiers in Rome; surprisingly to him, the present troops remained faithful to his son, and he had to flee to Constantine.
In the conference of Carnuntum
Carnuntum
Carnuntum was a Roman army camp on the Danube in the Noricum province and after the 1st century the capital of the Upper Pannonia province...
in the autumn of 308, Maxentius was once again denied recognition as legitimate emperor, and Licinius
Licinius
Licinius I , was Roman Emperor from 308 to 324. Co-author of the Edict of Milan that granted official toleration to Christians in the Roman Empire, for the majority of his reign he was the rival of Constantine I...
was appointed Augustus with the task of regaining the usurper's domain.
In 310, Maximian rebelled against Constantine while the emperor was on campaign against the Franks. Maximian had been sent south to Arles with part of Constantine's army to defend against attacks by Maxentius in southern Gaul. In Arles, Maximian announced that Constantine was dead and took up the imperial purple
Tyrian purple
Tyrian purple , also known as royal purple, imperial purple or imperial dye, is a purple-red natural dye, which is extracted from sea snails, and which was possibly first produced by the ancient Phoenicians...
. Despite offering bribes to any who would support him as emperor, most of Constantine's army remained loyal, and Maximian was compelled to leave. Constantine soon heard of the rebellion, abandoned his campaign against the Franks, and moved quickly to southern Gaul, where he confronted the fleeing Maximian at Massilia (Marseille
Marseille
Marseille , known in antiquity as Massalia , is the second largest city in France, after Paris, with a population of 852,395 within its administrative limits on a land area of . The urban area of Marseille extends beyond the city limits with a population of over 1,420,000 on an area of...
). The town was better able to withstand a longer siege than Arles, but it made little difference as loyal citizens opened the rear gates to Constantine. Maximian was captured, reproved for his crimes, and stripped of his title for the third and last time. Constantine granted Maximian some clemency but strongly encouraged his suicide. In July 310, Maximian hanged himself.
War of Constantine and Maxentius
By the middle of 310 Galerius had become too ill to involve himself in imperial politics. His final act survives: a letter to the provincials posted in Nicomedia on 30 April 311, proclaiming an end to the persecutions, and the resumption of religious toleration. He died soon after the edict's proclamation, destroying what little stability remained in the tetrarchy. Maximinus mobilized against Licinius, and seized Asia Minor. A hasty peace was signed on a boat in the middle of the Bosphorus. While Constantine toured Britain and Gaul, Maxentius prepared for war. He fortified northern Italy, and strengthened his support in the Christian community by allowing it to elect a new BishopBishop
A bishop is an ordained or consecrated member of the Christian clergy who is generally entrusted with a position of authority and oversight. Within the Catholic Church, Eastern Orthodox, Oriental Orthodox Churches, in the Assyrian Church of the East, in the Independent Catholic Churches, and in the...
of Rome
Diocese of Rome
The Diocese of Rome is a diocese of the Catholic Church in Rome, Italy. The bishop of Rome is the Pope, who is the Supreme Pontiff and leader of the Catholic Church...
, Eusebius
Pope Eusebius
Pope Saint Eusebius was pope in the year 309 or 310....
.
Maxentius' rule was nevertheless insecure. His early support dissolved in the wake of heightened tax rates and depressed trade; riots broke out in Rome and Carthage; and Domitius Alexander
Domitius Alexander
Lucius Domitius Alexander , probably born in Phrygia, was vicarius of Africa when Emperor Maxentius ordered him to send his son as hostage to Rome. Alexander refused and proclaimed himself emperor in 308....
was able to briefly usurp his authority in Africa. By 312, he was a man barely tolerated, not one actively supported, even among Christian Italians. In the summer of 311, Maxentius mobilized against Constantine while Licinius was occupied with affairs in the East. He declared war on Constantine, vowing to avenge his father's "murder". To prevent Maxentius from forming an alliance against him with Licinius, Constantine forged his own alliance with Licinius over the winter of 311–12, and offered him his sister Constantia in marriage. Maximin considered Constantine's arrangement with Licinius an affront to his authority. In response, he sent ambassadors to Rome, offering political recognition to Maxentius in exchange for a military support. Maxentius accepted. According to Eusebius, inter-regional travel became impossible, and there was military buildup everywhere. There was "not a place where people were not expecting the onset of hostilities every day".
Constantine's advisers and generals cautioned against preemptive attack on Maxentius; even his soothsayers recommended against it, stating that the sacrifices had produced unfavorable omens. Constantine, with a spirit that left a deep impression on his followers, inspiring some to believe that he had some form of supernatural guidance, ignored all these cautions. Early in the spring of 312, Constantine crossed the Cottian Alps
Cottian Alps
The Cottian Alps are a mountain range in the southwestern part of the Alps. They form the border between France and Italy...
with a quarter of his army, a force numbering about 40,000. The first town his army encountered was Segusium (Susa, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
), a heavily fortified town that shut its gates to him. Constantine ordered his men to set fire to its gates and scale its walls. He took the town quickly. Constantine ordered his troops not to loot the town, and advanced with them into northern Italy.
At the approach to the west of the important city of Augusta Taurinorum (Turin
Turin
Turin is a city and major business and cultural centre in northern Italy, capital of the Piedmont region, located mainly on the left bank of the Po River and surrounded by the Alpine arch. The population of the city proper is 909,193 while the population of the urban area is estimated by Eurostat...
, Italy), Constantine encountered a large force of heavily armed Maxentian cavalry. In the ensuing battle
Battle of Turin (312)
The Battle of Turin was fought in 312 between Roman emperor Constantine and the troops of his rival augustus, Maxentius. Constantine won the battle, giving an impressive display of the tactical skill which was to characterise his whole military career...
Constantine's army encircled Maxentius' cavalry, flanked them with his own cavalry, and dismounted them with blows from his soldiers' iron-tipped clubs. Constantine's armies emerged victorious. Turin refused to give refuge to Maxentius' retreating forces, opening its gates to Constantine instead. Other cities of the north Italian plain sent Constantine embassies of congratulation for his victory. He moved on to Milan, where he was met with open gates and jubilant rejoicing. Constantine rested his army in Milan until mid-summer 312, when he moved on to Brixia
Brixia
Brixia is the Latin name of the modern city of Brescia in Northern Italy.Its location was first settled in the 7th century BC by a tribe of Gauls , which were the inhabitants of this part of Italy before the Roman conquest . The name of the tribe was Cœnomani, and the name of the city comes from...
(Brescia
Brescia
Brescia is a city and comune in the region of Lombardy in northern Italy. It is situated at the foot of the Alps, between the Mella and the Naviglio, with a population of around 197,000. It is the second largest city in Lombardy, after the capital, Milan...
).
Brescia's army was easily dispersed, and Constantine quickly advanced to Verona
Verona
Verona ; German Bern, Dietrichsbern or Welschbern) is a city in the Veneto, northern Italy, with approx. 265,000 inhabitants and one of the seven chef-lieus of the region. It is the second largest city municipality in the region and the third of North-Eastern Italy. The metropolitan area of Verona...
, where a large Maxentian force was camped. Ruricius Pompeianus, general of the Veronese forces and Maxentius' praetorian prefect, was in a strong defensive position, since the town was surrounded on three sides by the Adige
Adige
The Adige is a river with its source in the Alpine province of South Tyrol near the Italian border with Austria and Switzerland. At in length, it is the second longest river in Italy, after the River Po with ....
. Constantine sent a small force north of the town in an attempt to cross the river unnoticed. Ruricius sent a large detachment to counter Constantine's expeditionary force, but was defeated. Constantine's forces successfully surrounded the town and laid siege. Ruricius gave Constantine the slip and returned with a larger force to oppose Constantine. Constantine refused to let up on the siege, and sent only a small force to oppose him. In the desperately fought encounter
Battle of Verona (312)
The Battle of Verona was fought in 312 between the forces of the Roman emperors Constantine I and Maxentius. Maxentius' forces were defeated, and Ruricius Pompeianus, the most senior Maxentian commander, was killed in the fighting.-Background:...
that followed, Ruricius was killed and his army destroyed. Verona surrendered soon afterwards, followed by Aquileia
Aquileia
Aquileia is an ancient Roman city in what is now Italy, at the head of the Adriatic at the edge of the lagoons, about 10 km from the sea, on the river Natiso , the course of which has changed somewhat since Roman times...
, Mutina (Modena
Modena
Modena is a city and comune on the south side of the Po Valley, in the Province of Modena in the Emilia-Romagna region of Italy....
), and Ravenna
Ravenna
Ravenna is the capital city of the Province of Ravenna in the Emilia-Romagna region of Italy and the second largest comune in Italy by land area, although, at , it is little more than half the size of the largest comune, Rome...
. The road to Rome was now wide open to Constantine.
Maxentius prepared for the same type of war he had waged against Severus and Galerius: he sat in Rome and prepared for a siege. He still controlled Rome's praetorian guards, was well-stocked with African grain, and was surrounded on all sides by the seemingly impregnable Aurelian Walls
Aurelian Walls
The Aurelian Walls is a line of city walls built between 271 and 275 in Rome, Italy, during the reign of the Roman Emperors Aurelian and Probus....
. He ordered all bridges across the Tiber
Tiber
The Tiber is the third-longest river in Italy, rising in the Apennine Mountains in Emilia-Romagna and flowing through Umbria and Lazio to the Tyrrhenian Sea. It drains a basin estimated at...
cut, reportedly on the counsel of the gods, and left the rest of central Italy undefended; Constantine secured that region's support without challenge. Constantine progressed slowly along the Via Flaminia
Via Flaminia
The Via Flaminia was an ancient Roman road leading from Rome over the Apennine Mountains to Ariminum on the coast of the Adriatic Sea, and due to the ruggedness of the mountains was the major option the Romans had for travel between Etruria, Latium and Campania and the Po Valley...
, allowing the weakness of Maxentius to draw his regime further into turmoil. Maxentius' support continued to weaken: at chariot races on 27 October, the crowd openly taunted Maxentius, shouting that Constantine was invincible. Maxentius, no longer certain that he would emerge from a siege victorious, built a temporary boat bridge across the Tiber in preparation for a field battle against Constantine. On 28 October 312, the sixth anniversary of his reign, he approached the keepers of the Sibylline Books
Sibylline Books
The Sibylline Books or Libri Sibyllini were a collection of oracular utterances, set out in Greek hexameters, purchased from a sibyl by the last king of Rome, Tarquinius Superbus, and consulted at momentous crises through the history of the Republic and the Empire...
for guidance. The keepers prophesied that, on that very day, "the enemy of the Romans" would die. Maxentius advanced north to meet Constantine in battle.
Maxentius organized his forces—still twice the size of Constantine's—in long lines facing the battle plain, with their backs to the river. Constantine's army arrived at the field bearing unfamiliar symbols on either its standards or its soldiers' shields. According to Lactantius, Constantine was visited by a dream the night before the battle, wherein he was advised "to mark the heavenly sign of God on the shields of his soldiers...by means of a slanted letter X with the top of its head bent round, he marked Christ on their shields." Eusebius describes another version, where, while marching at midday, "he saw with his own eyes in the heavens a trophy of the cross arising from the light of the sun, carrying the message, In Hoc Signo Vinces or "Conquer By This"; in Eusebius's account, Constantine had a dream the following night, in which Christ appeared with the same heavenly sign, and told him to make a standard, the labarum
Labarum
The labarum was a vexillum that displayed the "Chi-Rho" symbol ☧, formed from the first two Greek letters of the word "Christ" — Chi and Rho . It was used by the Roman emperor Constantine I...
, for his army in that form. Eusebius is vague about when and where these events took place, but it enters his narrative before the war against Maxentius begins. Eusebius describes the sign as Chi
Chi (letter)
Chi is the 22nd letter of the Greek alphabet, pronounced as in English.-Greek:-Ancient Greek:Its value in Ancient Greek was an aspirated velar stop .-Koine Greek:...
(Χ) traversed by Rho
Rho (letter)
Rho is the 17th letter of the Greek alphabet. In the system of Greek numerals, it has a value of 100. It is derived from Semitic resh "head"...
(Ρ), or ☧ a symbol representing the first two letters of the Greek spelling of the word Christos or Christ. The Eusebian description of the vision has been explained as a "solar halo
Halo (optical phenomenon)
A halo from Greek ἅλως; also known as a nimbus, icebow or gloriole) is an optical phenomenon produced by ice crystals creating colored or white arcs and spots in the sky. Many are near the sun or moon but others are elsewhere and even in the opposite part of the sky...
", a meteorological phenomenon which can produce similar effects. In 315 a medallion was issued at Ticinum showing Constantine wearing a helmet emblazoned with the Chi-Rho, and coins issued at Siscia in 317/18 repeat the image. The figure was otherwise rare, however, and is uncommon in imperial iconography and propaganda before the 320s.
Constantine deployed his own forces along the whole length of Maxentius' line. He ordered his cavalry to charge, and they broke Maxentius' cavalry. He then sent his infantry against Maxentius' infantry, pushing many into the Tiber where they were slaughtered and drowned. The battle was brief: Maxentius' troops were broken before the first charge. Maxentius' horse guards and praetorians initially held their position, but broke under the force of a Constantinian cavalry charge; they also broke ranks and fled to the river. Maxentius rode with them, and attempted to cross the bridge of boats, but he was pushed by the mass of his fleeing soldiers into the Tiber, and drowned.
Constantine entered Rome on 29 October. He staged a grand adventus
Adventus (ceremony)
The adventus was a ceremony in ancient Rome, in which an emperor was formally welcomed into a city either during a progress or after a military campaign, often Rome. The term is also used to refer to artistic depicitions of such ceremonies. Its 'opposite' is the profectio.-External links:*...
in the city, and was met with popular jubilation. Maxentius' body was fished out of the Tiber and decapitated. His head was paraded through the streets for all to see. After the ceremonies, Maxentius' disembodied head was sent to Carthage
Carthage
Carthage , implying it was a 'new Tyre') is a major urban centre that has existed for nearly 3,000 years on the Gulf of Tunis, developing from a Phoenician colony of the 1st millennium BC...
; at this Carthage would offer no further resistance.
War of Licinius and Maximinus Daia
Meanwhile to the east, on Galerius’ death in 311 the eastern provinces were divided between Maximinus DaiaMaximinus
Maximinus II , also known as Maximinus Daia or Maximinus Daza, was Roman Emperor from 308 to 313. He was born of Dacian peasant stock to the half sister of the emperor Galerius near their family lands around Felix Romuliana; a rural area then in the Danubian region of Moesia, now Eastern Serbia.He...
and Licinius
Licinius
Licinius I , was Roman Emperor from 308 to 324. Co-author of the Edict of Milan that granted official toleration to Christians in the Roman Empire, for the majority of his reign he was the rival of Constantine I...
. Daia was unhappy that Licinius had been made senior emperor by Galerius, and took the first available opportunity to declare himself as emperor. Licinius held the eastern European provinces, while Daia took possession of the Asiatic provinces.
In the autumn of 312, while Constantine was fighting Maxentius, Daia was busy campaigning against the Armenians. He had returned to Syria by February 313 when discovered the alliance that had been forged by Constantine and Licinius. He in turn entered into a secret alliance with Maxentius, but was soon flustered by the death of Maxentius. Deciding to take the initiative, Daia left Syria with 70,000 men and reached Bythinia, although harsh weather he encountered along the way had gravely weakened his army. In April 313, he crossed the Bosporus
Bosporus
The Bosphorus or Bosporus , also known as the Istanbul Strait , is a strait that forms part of the boundary between Europe and Asia. It is one of the Turkish Straits, along with the Dardanelles...
and went to Byzantium
Byzantium
Byzantium was an ancient Greek city, founded by Greek colonists from Megara in 667 BC and named after their king Byzas . The name Byzantium is a Latinization of the original name Byzantion...
, which was held by Licinius' troops. Undeterred, he took the town after an eleven-day siege. He moved to Heraclea, which he captured after a short siege, before moving his forces to the first posting station. With a much smaller body of men, possibly around 30,000, Licinius arrived at Adrianople while Daia was still besieging Heraclea
Heraclea Pontica
Heraclea Pontica , an ancient city on the coast of Bithynia in Asia Minor, at the mouth of the river Lycus. It was founded by the Greek city-state of Megara c.560-558 and was named after Heracles who the Greeks believed entered the underworld at a cave on the adjoining Archerusian promontory .The...
. On 30 April 313, the two armies clashed at the Battle of Tzirallum
Battle of Tzirallum
The Battle of Tzirallum was one of the Civil Wars of the Tetrarchy fought in 313 near Heraclea between the Roman armies of emperors Licinius and Maximinus.-Background:...
, and in the ensuing battle Daia's forces were crushed. Ridding himself of the imperial purple and dressing like a slave, Daia fled to Nicomedia
Nicomedia
Nicomedia was an ancient city in what is now Turkey, founded in 712/11 BC as a Megarian colony and was originally known as Astacus . After being destroyed by Lysimachus, it was rebuilt by Nicomedes I of Bithynia in 264 BC under the name of Nicomedia, and has ever since been one of the most...
. Believing he still had a chance to come out victorious, Daia attempted to stop the advance of Licinius at the Cilician Gates
Cilician Gates
The Cilician Gates or Gülek Pass is a pass through the Taurus Mountains connecting the low plains of Cilicia to the Anatolian Plateau, by way of the narrow gorge of the Gökoluk River. Its highest elevation is about 1000m....
by establishing fortifications there. Unfortuately for Daia, Licinius' army succeeded in breaking through, forcing Daia to retreat to Tarsus where Licinius continued to press him on land and sea. The war between them only ended with Daia’s death in August 313.
Wars of Constantine and Licinius
Licinius
Licinius I , was Roman Emperor from 308 to 324. Co-author of the Edict of Milan that granted official toleration to Christians in the Roman Empire, for the majority of his reign he was the rival of Constantine I...
in Milan
Milan
Milan is the second-largest city in Italy and the capital city of the region of Lombardy and of the province of Milan. The city proper has a population of about 1.3 million, while its urban area, roughly coinciding with its administrative province and the bordering Province of Monza and Brianza ,...
to secure their alliance by the marriage of Licinius and Constantine's half-sister Constantia
Flavia Julia Constantia
Flavia Julia Constantia was the daughter of the Roman Emperor Constantius Chlorus and his second wife, Flavia Maximiana Theodora....
. During this meeting, the emperors agreed on the so-called Edict of Milan
Edict of Milan
The Edict of Milan was a letter signed by emperors Constantine I and Licinius that proclaimed religious toleration in the Roman Empire...
, officially granting full tolerance to "Christianity and all" religions in the Empire. The document had special benefits for Christians, legalizing their religion and granting them restoration for all property seized during Diocletian's persecution. It repudiates past methods of religious coercion and used only general terms to refer to the divine sphere — "Divinity" and "Supreme Divinity", summa divinitas. The conference was cut short, however, when news reached Licinius that his rival Maximin had crossed the Bosporus
Bosporus
The Bosphorus or Bosporus , also known as the Istanbul Strait , is a strait that forms part of the boundary between Europe and Asia. It is one of the Turkish Straits, along with the Dardanelles...
and invaded European territory. Licinius departed and eventually defeated Maximinus, gaining control over the entire eastern half of the Roman Empire. Relations between the two remaining emperors deteriorated, though, and either in 314 or 316, Constantine and Licinius fought against one another in the war of Cibalae
Battle of Cibalae
The Battle of Cibalae was fought on October 8, 314 , between the two Roman emperors Constantine I and Licinius. The site of the battle was approximately 350 kilometers within the territory of Licinius...
, with Constantine being victorious. They clashed again in the Battle of Campus Ardiensis
Battle of Mardia
The Battle of Mardia, also known as Battle of Campus Mardiensis or Battle of Campus Ardiensis, was fought, probably at modern Harmanli in Thrace, in late 316/early 317 between the forces of Roman Emperors Constantine I and Licinius....
in 317, and agreed to a settlement in which Constantine's sons Crispus
Crispus
Flavius Julius Crispus , also known as Flavius Claudius Crispus and Flavius Valerius Crispus, was a Caesar of the Roman Empire. He was the first-born son of Constantine I and Minervina.-Birth:...
and Constantine II
Constantine II (emperor)
Constantine II , was Roman Emperor from 337 to 340. Co-emperor alongside his brothers, his short reign saw the beginnings of conflict emerge between the sons of Constantine the Great, and his attempt to exert his perceived rights of primogeniture ended up causing his death in a failed invasion of...
, and Licinius' son Licinianus were made caesars
Caesar (title)
Caesar is a title of imperial character. It derives from the cognomen of Julius Caesar, the Roman dictator...
.
In the year 320, Licinius
Licinius
Licinius I , was Roman Emperor from 308 to 324. Co-author of the Edict of Milan that granted official toleration to Christians in the Roman Empire, for the majority of his reign he was the rival of Constantine I...
reneged on the religious freedom promised by the Edict of Milan
Edict of Milan
The Edict of Milan was a letter signed by emperors Constantine I and Licinius that proclaimed religious toleration in the Roman Empire...
in 313 and began to oppress Christians anew. It became a challenge to Constantine in the west, climaxing in the great civil war of 324. Licinius, aided by Goth
Goths
The Goths were an East Germanic tribe of Scandinavian origin whose two branches, the Visigoths and the Ostrogoths, played an important role in the fall of the Roman Empire and the emergence of Medieval Europe....
mercenaries
Mercenary
A mercenary, is a person who takes part in an armed conflict based on the promise of material compensation rather than having a direct interest in, or a legal obligation to, the conflict itself. A non-conscript professional member of a regular army is not considered to be a mercenary although he...
, represented the past and the ancient Pagan
Paganism
Paganism is a blanket term, typically used to refer to non-Abrahamic, indigenous polytheistic religious traditions....
faiths. Constantine and his Franks
Franks
The Franks were a confederation of Germanic tribes first attested in the third century AD as living north and east of the Lower Rhine River. From the third to fifth centuries some Franks raided Roman territory while other Franks joined the Roman troops in Gaul. Only the Salian Franks formed a...
marched under the standard of the labarum
Labarum
The labarum was a vexillum that displayed the "Chi-Rho" symbol ☧, formed from the first two Greek letters of the word "Christ" — Chi and Rho . It was used by the Roman emperor Constantine I...
, and both sides saw the battle in religious terms. Supposedly outnumbered, but fired by their zeal, Constantine's army emerged victorious in the Battle of Adrianople
Battle of Adrianople (324)
The Battle of Adrianople was fought on July 3, 324 during a Roman civil war, the second to be waged between the two emperors Constantine I and Licinius; Licinius suffered a heavy defeat.-Background:...
. Licinius fled across the Bosphorus and appointed Martius Martinianus, the commander of his bodyguard, as Caesar, but Constantine next won the Battle of the Hellespont
Battle of the Hellespont
The Battle of the Hellespont, consisting of two separate naval clashes, was fought in 324 between a Constantinian fleet, led by the eldest son of Constantine I, Crispus; and a larger fleet under Licinius' admiral, Abantus...
, and finally the Battle of Chrysopolis
Battle of Chrysopolis
The Battle of Chrysopolis was fought on 18 September 324 at Chrysopolis , near Chalcedon , between the two Roman emperors Constantine I and Licinius. The battle was the final encounter between the two emperors. After his navy's defeat in the Battle of the Hellespont, Licinius withdrew his forces...
on 18 September 324. Licinius and Martinianus surrendered to Constantine at Nicomedia on the promise their lives would be spared: they were sent to live as private citizens in Thessalonica and Cappadocia respectively, but in 325 Constantine accused Licinius of plotting against him and had them both arrested and hanged; Licinius's son (the son of Constantine's half-sister) was also eradicated. Thus Constantine became the sole emperor of the Roman Empire, ending the Civil Wars of the Tetrarchy.