On This Day

Roman Emperor Constantine the Great is said to have received his famous Vision of the Cross

Constantine I (27 February 272 – 22 May 337), also known as Constantine the Great, or known mononymously as Constantine, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to...

Constantine I (27 February 272 – 22 May 337), also known as Constantine the Great, or known mononymously as Constantine, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a pivotal role in elevating the status of Christianity in Rome, the Edict of Milan decriminalising Christian practice and ceasing Christian persecution. This was a turning point in the Christianisation of the Roman Empire.

Historical Significance

Constantine I (27 February 272 – 22 May 337), also known as Constantine the Great, or known mononymously as Constantine, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity.

Key People

Constantine the Great

Roman emperor from 306 to 337

Roman emperor from 306 to 337

Events Before

  1. Marcellus I begins his reign as Catholic Pope, serving until his death in 309

    Marcellus I begins his reign as Catholic Pope, serving until his death in 309

  2. St. Eusebius begins his reign as Catholic Pope

    St. Eusebius begins his reign as Catholic Pope

  3. St. Eusebius ends his reign as Catholic Pope

    St. Eusebius ends his reign as Catholic Pope

  4. Roman Emperor Galerius issues the Edict of Toleration, ending the persecution of Christians in the Roman Empire

    Early Christians were heavily persecuted throughout the Roman Empire until the 3rd century.

  5. St Miltiades begins his reign as Catholic Pope

    St Miltiades begins his reign as Catholic Pope

Events After

  1. Start of Roman (Pontifical) Indiction

    Start of Roman (Pontifical) Indiction

  2. Licinius unifies the entire Eastern Roman Empire under his rule

    The history of the Jews in the Roman Empire traces the interaction of Jews and Romans during the period of the Roman Empire (27 BC – 476 AD).

  3. St Silvester I begins his reign as Catholic Pope

    St Silvester I begins his reign as Catholic Pope

  4. BC Battle of Crannon between Athens and Macedon following the death of Alexander the Great

    The Battle of the Echinades was one of the naval battles of the Lamian War (323–322 BC), fought between the Macedonian navy under Cleitus the White and the Athenian navy.

More from the 310s

Frequently Asked Questions

What happened on October 27, 312?
Constantine I (27 February 272 – 22 May 337), also known as Constantine the Great, or known mononymously as Constantine, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a pivotal role in elevating the status of Christianity in Rome, the Edict of Milan decriminalising Christian practice and ceasing Christian persecution. This was a turning point in the Christianisation of the Roman Empire.
Why is Roman Emperor Constantine the Great is said to have received his famous Visio... significant?
Constantine I (27 February 272 – 22 May 337), also known as Constantine the Great, or known mononymously as Constantine, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity.
Who was involved in Roman Emperor Constantine the Great is said to have received his famous Visio...?
Key figures include Constantine the Great (Roman emperor from 306 to 337).

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