How Constantine the Great reunited the Roman Empire

After years of being an imperial hostage, Constantine reunited with his father, the Western Augustus Constantius Chlorus, in 305. Father and son went on to campaign against the Picts in Scotland. Sadly, their reunion was short-lived. Constantius died at York on 25 July, 306, leaving Constantine to inherit his troops and domains in Britain and Gaul. 1

The road to supremacy in the Roman Empire was not an easy one for Constantine. Firstly, the Tetrarchy created many powerful rivals that Constantine had to overcome. There was the Eastern Augustus Galerius and his Caesar Maximinus II Daia. In the West there was the Caesar Severus and the rebel Augusti Maximian and Maxentius. Secondly, although his father’s troops had proclaimed him Augustus of the West, it was illegitimate without the approval of Galerius. Lastly, Constantine’s newly inherited domains also faced attacks from barbarian tribes. In this article I shall outline how Constantine overcame these problems to reunite the Roman Empire. 2

Image Credit: dsmoljanovic

How Constantine dealt with the powerful Eastern Augustus Galerius

The Tetrarchy, introduced by the Roman emperor Diocletian in 293, ruled the Roman Empire. When Constantius died, his troops acclaimed Constantine as the new Western Augustus. But Constantine knew that he needed the approval of the new Eastern Augustus Galerius to legitimize his claim. Prudently, Constantine wrote to Galerius to seek his approval. 3

Galerius was furious at the audacity of Constantine. But he had little choice; Constantine had his father’s troops to back up his claim. To avoid a civil war, Galerius made Constantine Caesar while appointing Severus as Augustus of the West. For the moment, Constantine deferred to the wishes of Galerius. He was not ready to challenge Galerius yet. Although he was merely Caesar, Constantine had skilfully legitimized his position. 4

Meanwhile, Galerius wasted his energies against the rebel emperor Maxentius in a futile attempt to subdue him. Fortune however smiled on Constantine with the death of Galerius in 311. 5

Why Maximian proved to be a double-edged sword for Constantine

When his son Maxentius rebelled in 306, the former Western Augustus Maximian returned from his enforced retirement to join him. Resuming his former title, Maximian allied with and recognized Constantine as a fellow Augustus. Then in 307, Maximian married his daughter Fausta to Constantine to strengthen their bonds. This was a mutually beneficial arrangement. Constantine obtained the right to rule as Augustus through Maximian. Meanwhile Maxentius and Maximian gained a powerful ally against Galerius. 6

When Maximian fell out with his son in 307 or 308, Constantine gladly provided shelter to his father-in-law. But in 310, Maximian tried to seize power for himself by rebelling against Constantine. He may have succeeded if Fausta had not betrayed him to Constantine. Constantine went on to defeat Maximian and forced him to commit suicide. 7

Having killed Maximian, Constantine could no longer legitimize his reign through him. Instead, Constantine resolved this problem by claiming to be the descendant of the Roman emperor Claudius II Gothicus (268-270). By creating this fictitious Claudian and Constantinian dynasty, Constantine claimed the right to rule through his newfound ancestor. In one move, Constantine made the Tetrarchy and Galerius irrelevant to him. 8

How Constantine used Maxentius to win the Western Roman Empire

The recognition of Constantine as Caesar by Galerius destabilized the Tetrarchy. It caused Maxentius to rebel in Rome on 28 October, 306 and to proclaim himself Augustus of the West. Maxentius was the son of the former emperor Maximian and the son-in-law of Galerius. But Galerius did not appoint him as Caesar when his father retired. With the support of the disgruntled Praetorian Guards, Maxentius took Italy and North Africa for himself. Despite his dislike of Constantine, he prudently formed an alliance with him against Galerius. 9

Maxentius went on to repel attacks from Severus and Galerius. He even managed to capture and kill Severus. But Galerius merely replaced the slain Severus with Licinius whom he appointed as Augustus. Meanwhile, Constantine chose not to get involved in the Italian conflicts. Instead he used this opportunity to build up his strength and to crush the barbarian threats to his domains. 10

After Galerius died in 311, the East belonged to Licinius and Maximinus II Daia. At this point, Constantine felt strong enough to attack Maxentius for control of the Western Roman Empire. Therefore, he formed an alliance with Licinius against Maxentius and Maximinus. 11

In 312, despite unfavourable circumstances, Constantine crossed the Alps and attacked Maxentius in Italy. From the start, Constantine portrayed himself as the liberator of the Romans from the tyranny of Maxentius’s harsh rule. He gave strict orders to his troops not to pillage the towns they captured. Because of this, many towns opened their gates to him. Through his courage, sound military strategies and tactics, Constantine finally defeated and killed Maxentius at the Battle of Milvian Bridge on 28 October 312. Constantine attributed this victory to his newfound religion; Christianity. By the grace of the Christian God, Constantine was now the sole ruler of the Western Roman Empire. 12

Image Credit: Spider

How Constantine overcame Licinius to become sole Roman Emperor

Galerius elevated Licinius to the rank of Augustus on 26 December 308 to replace the slain Severus. This was highly irregular because Licinius had never served as Caesar. After Constantine invented his own imperial ancestry, Licinius also did the same. He claimed to be a descendant of the Roman emperor Phillip the Arab (244-249). To expand his power, he allied with Constantine and married his half-sister Constantia in 313. With the Western Roman Empire under Constantine’s control, Licinius went on to defeat Maximinus for control of the East in 313. Now only two men remained to contend for the Roman Empire. 13

The peace between Constantine and Licinius held till 316. Tensions between them had been building for sometime and they finally clashed on 8 October 316. Although the odds were against Constantine, he emerged victorious over Licinius. In return for the cessation of most of the Balkans and recognition from Licinius as senior emperor, Constantine agreed to a renewed peace. Thus the first Licinian war ended with Constantine in a stronger position. 14

Given the ambitions of both men, the peace could not last forever. When Licinius began to persecute the Christians in his domains, he gave Constantine a pretext to attack him. The second Licinian war broke out on 3 July 324 outside Hadrianople. Constantine repeatedly defeated Licinius on land and sea, forcing him to flee to Nicomedia in Asia Minor. There Constantia persuaded her husband to surrender. Then she pleaded with her brother to spare her husband’s life. Constantine agreed. He forced Licinius and his Augustus Martinian into retirement and confiscated their possessions. But in the spring of 325, he had both men killed as a precaution. In this manner, Constantine became the sole ruler of the Roman Empire. 15

Reflections of the Vizier

Constantine had boundless ambition. Over the course of 20 years, he patiently eliminated his rivals one by one. As long as they stood in his path, he spared no one. Not friends or relatives. His success is all the more amazing for its scope, the obstacles he slowly overcame, and the time he invested to achieve it.

What are your thoughts about Constantine’s achievements? Was it worth all the bloodshed? Could he have reunited the Roman Empire through benevolence instead? Or could he have at least spared the lives of his enemies once he had destroyed their power?

If you enjoyed this article, subscribe to my blog via rss or email and get updated whenever I publish a new article.


Grant, Michael. The Emperor Constantine. England: Orion Books Ltd, 1998.

Norwich, John Julius. Byzantium: The Early Centuries. England: Penguin Books, 1990.

Treadgold, Warren. A History of the Byzantine State and Society. California: Stanford University Press, 1997.

If you enjoyed this post, make sure you subscribe to my RSS feed!
  1. Michael Grant, The Emperor Constantine (England: Orion Books Ltd, 1998), 19-23; John Julius Norwich, Byzantium: The Early Centuries (England: Penguin Books, 1990), 33-35; Warren Treadgold, A History of the Byzantine State and Society (California: Stanford University Press, 1997), 28. []
  2. Grant, The Emperor Constantine, 17-48, 52; Norwich, Byzantium: The Early Centuries, 33-50; Treadgold, A History of the Byzantine State and Society, 28-36. []
  3. Grant, The Emperor Constantine, 17-19, 23; Norwich, Byzantium: The Early Centuries, 33, 35; Treadgold, A History of the Byzantine State and Society, 13-19, 28. []
  4. Grant, The Emperor Constantine, 23; Norwich, Byzantium: The Early Centuries, 35; Treadgold, A History of the Byzantine State and Society, 28. []
  5. Grant, The Emperor Constantine, 24-26, 33; Norwich, Byzantium: The Early Centuries, 36-37; Treadgold, A History of the Byzantine State and Society, 28-30. []
  6. Grant, The Emperor Constantine, 24; Norwich, Byzantium: The Early Centuries, 36; Treadgold, A History of the Byzantine State and Society, 28-29. []
  7. Grant, The Emperor Constantine, 24-26; Norwich, Byzantium: The Early Centuries, 37; Treadgold, A History of the Byzantine State and Society, 29. []
  8. Grant, The Emperor Constantine, 26-27. []
  9. Grant, The Emperor Constantine, 23-24; Norwich, Byzantium: The Early Centuries, 36; Treadgold, A History of the Byzantine State and Society, 28-29. []
  10. Grant, The Emperor Constantine, 24, 52; Norwich, Byzantium: The Early Centuries, 35-36; Treadgold, A History of the Byzantine State and Society, 29. []
  11. Grant, The Emperor Constantine, 33; Norwich, Byzantium: The Early Centuries, 37; Treadgold, A History of the Byzantine State and Society, 31. []
  12. Grant, The Emperor Constantine, 33-39, 146-147; Norwich, Byzantium: The Early Centuries, 37-40; Treadgold, A History of the Byzantine State and Society, 31-33. []
  13. Grant, The Emperor Constantine, 25, 27, 33, 39-40; Norwich, Byzantium: The Early Centuries, 37, 44-46; Treadgold, A History of the Byzantine State and Society, 29-33. []
  14. Grant, The Emperor Constantine, 40-44; Norwich, Byzantium: The Early Centuries, 46-47; Treadgold, A History of the Byzantine State and Society, 33-34. []
  15. Grant, The Emperor Constantine, 44-48; Norwich, Byzantium: The Early Centuries, 47-50; Treadgold, A History of the Byzantine State and Society, 34-36. []
3 Comments Post a Comment
  1. Hello. Fantastic job, if I wasn’t so busy with my school work I read your full site. Thanks!

  2. The Vizier says:

    Hi Cortez

    Thanks for the compliment. You can always read my site when you are free.

  3. Your blog its amazing thx a lot !

Leave a Reply


© 2009-2018 Neo Byzantium All Rights Reserved -- Copyright notice by Blog Copyright

SEO Powered by Platinum SEO from Techblissonline