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Constantine the Great

Constantine the Great, also known as Constantine I, was Roman emperor from 306 to 337 CE and the first Roman emperor to convert to Christianity.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 27, 2026|2 min read| Fact-checked

Constantine the Great, also known as Constantine I, was Roman emperor from 306 to 337 CE and the first Roman emperor to convert to Christianity. He played a major role in the Christianisation of the Roman Empire, issued the Edict of Milan with Licinius, and founded Constantinople as a new imperial capital.

Early life and rise to power

Constantine was born in Naissus and was the son of Constantius I Chlorus, who later became Roman emperor. He rose to power after being proclaimed emperor in 306 following his father's death.

Religious policy

Constantine's reign marked a major shift in imperial policy toward Christianity. The Edict of Milan in 313 granted tolerance to Christians and helped end systematic persecution.

Founding of Constantinople

In 324, Constantine established Constantinople on the site of Byzantium and made it the capital of the Roman Empire. The city became one of the most important political and religious centres of the medieval world.

Legacy

Constantine's rule reshaped Roman politics, religion, and imperial administration. Historians often describe him as one of the most influential emperors in late antiquity.

Key facts

  • He ruled the Roman Empire from 306 to 337 CE.
  • He is widely regarded as the first Roman emperor to convert to Christianity.
  • He and Licinius issued the Edict of Milan in 313, which ended official persecution of Christians in the empire.
  • He founded Constantinople, renaming the former Byzantium and making it the imperial capital.
  • His reign is considered a turning point in the Christianisation of the Roman Empire.
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Canadian context

Constantine the Great is studied in Canadian history, classics, religious studies, and Byzantine studies as a key figure in the transition from the pagan Roman Empire to a Christian imperial tradition.

Frequently asked questions

Who was Constantine the Great?
Constantine the Great was a Roman emperor who ruled from 306 to 337 CE and is best known for promoting Christianity within the empire.
Why is Constantine called “the Great”?
He is remembered for military success, political consolidation, and his support for Christianity, which transformed Roman imperial history.
What was the Edict of Milan?
The Edict of Milan was an agreement in 313 that granted religious tolerance to Christians and ended official persecution in the Roman Empire.
Did Constantine found Constantinople?
Yes. He founded Constantinople on the site of Byzantium and made it the empire’s capital.
Was Constantine the first Christian Roman emperor?
He is commonly described as the first Roman emperor to profess or convert to Christianity, though the timing and nature of his conversion remain debated by historians.

References

  1. Wikipediahttps://en.wikipedia.org/wiki/Constantine_the_Great
    Supports: Basic chronology, reign dates, conversion to Christianity, Edict of Milan, and founding of Constantinople.
  2. Britannicahttps://www.britannica.com/biography/Constantine-I-Roman-emperor
    Supports: Biography, reign dates, Edict of Milan, Constantinople, and historical significance.
  3. Britannicahttps://www.britannica.com/summary/Constantine-I-Roman-emperor
    Supports: Summary facts on birth, death, conversion, Edict of Milan, and capital relocation.
  4. Encyclopedia.comhttps://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/constantine-i-great-roman-emperor
    Supports: Parentage, reign, and Roman imperial background.
  5. World History Encyclopediahttps://www.worldhistory.org/Constantine_I/
    Supports: Reign dates and general historical role.