Emperor Constantine legalization and spread of Christianity

Emperor Constantine, also known as Constantine the Great, was one of the most influential rulers of the Roman Empire. He reigned from A.D. 306 to 337 and is best known for his role in the legalization and spread of Christianity.

The Edict of Milan (A.D. 313) – Constantine, along with co-emperor Licinius, issued this edict, granting religious tolerance to Christians and effectively ending Roman persecution of the faith.

Battle of the Milvian Bridge (A.D. 312) – Before this decisive battle against his rival Maxentius, Constantine reportedly saw a vision of a cross in the sky with the words, “In hoc signo vinces” (“In this sign, you will conquer”). He ordered his soldiers to mark their shields with the Chi-Rho (☧), an early Christian symbol, and won the battle.

Council of Nicaea (A.D. 325) – Constantine convened the first ecumenical council of Christian bishops to settle theological disputes, particularly concerning Arianism. This council produced the Nicene Creed, which became a foundational statement of Christian belief.

Founding of Constantinople (A.D. 330) – Constantine established a new imperial capital, Byzantium, later renamed Constantinople (modern-day Istanbul). This city became a center of Christianity and Eastern Roman (Byzantine) power.

Christian Patronage – While he was baptized only shortly before his death, Constantine heavily supported Christianity by funding church construction, favoring Christian officials, and promoting Christian moral values in law.

Controversies:

Some argue Constantine’s conversion to Christianity was more political than spiritual, as he retained some pagan elements in governance.
He executed his son Crispus and wife Fausta under mysterious circumstances, which has led to speculation about his moral character.
Though he promoted Christianity, he maintained the title Pontifex Maximus, the high priest of Roman paganism.

Legacy:

Constantine’s reign marked a turning point in history, shifting the Roman Empire toward a Christian identity. His policies laid the foundation for the Byzantine Empire, and his influence on Christianity remains significant to this day.

Emperor Constantine the Great died in A.D. 337 his empire was divided among his three surviving sons:

Constantine II (ruled 337–340) – He took control of Gaul, Britain, and Spain.

Constantius II (ruled 337–361) – He ruled over the Eastern Roman Empire, including Egypt and Asia Minor.

Constans I (ruled 337–350) – He controlled Italy, North Africa, and the Balkans.


What Happened Next?

Constantine II tried to invade his brother Constans’ territory but was killed in battle in A.D. 340.

Constans I ruled alone in the West until he was assassinated by the usurper Magnentius in A.D. 350.

Constantius II eventually defeated Magnentius and became the sole ruler of the Roman Empire in A.D. 353.

Constantius II ruled until his death in A.D. 361, when his cousin Julian the Apostate took over and tried to restore paganism.

Julian the Apostate (A.D. 331–363), born Flavius Claudius Julianus, was a Roman emperor from A.D. 361 to 363. He is known for his attempt to restore paganism and undo the Christian influence established by Constantine the Great and his successors. Because of this, he earned the title "the Apostate" from Christian historians.

Julian as Emperor (A.D. 361–363)
Julian became the sole emperor after Constantius II died in A.D. 361. He quickly revealed his pagan beliefs and launched a campaign to weaken Christianity.

His Anti-Christian Policies

Restoring Pagan Temples – He reopened and funded old Roman temples and reinstated sacrifices to the gods.
Reducing Christian Privileges – He removed tax exemptions and state funding for Christian churches.
Expelling Christians from Government and Education – He banned Christians from teaching classical literature, hoping to prevent them from shaping Roman culture.
Failed Jewish Temple Rebuilding – He attempted to rebuild the Jewish Temple in Jerusalem (possibly to undermine Christian claims), but mysterious events, including earthquakes and fires, stopped the project.

Military Campaign and Death

His campaign started well, but he was mortally wounded during a Persian counterattack. Accounts vary on how he died—some say a Persian spear struck him, while others claim a Christian soldier assassinated him.
Before dying, he supposedly said, “Thou hast conquered, O Galilean”, referring to Jesus Christ.

Jovian (Flavius Jovianus, A.D. 331–364) was the Roman emperor from A.D. 363 to 364. He ruled for only eight months, but his reign was significant because he restored Christianity as the favored religion of the empire after the anti-Christian policies of Julian the Apostate.

How He Became Emperor

Julian the Apostate died during his failed Persian campaign in A.D. 363.
The Roman army, stranded deep in Persian territory and needing a new leader, quickly chose Jovian, a high-ranking officer in Julian’s army.
Unlike Julian, Jovian was a devout Christian and wasted no time in undoing Julian’s pagan policies. 

Major Actions as Emperor

1. Restoring Christianity
• He reinstated Christian privileges, funding churches and reversing Julian’s anti-Christian laws.
• He reaffirmed the Nicene Creed, siding against Arianism, a major theological dispute at the time.
• He stopped pagan sacrifices and expelled pagan philosophers from imperial favor.
2. Ending the War with Persia
• Trapped in enemy territory, Jovian was forced to sign a humiliating peace treaty with the Sassanid Persians.
• The treaty required Rome to give up five provinces east of the Tigris River and abandon key fortresses.
• Though necessary to save the army, this weakened Rome’s position in the East.
3. His Mysterious Death
• Jovian died suddenly in February A.D. 364, just eight months after becoming emperor.
• Theories about his death include:
o Accidental suffocation from a charcoal fire in his tent (possible carbon monoxide poisoning).
o Poisoning, possibly by political rivals.

Legacy
Jovian’s short reign was transitional—he ensured that Rome remained a Christian empire, paving the way for future emperors like Valentinian I and Theodosius I (who later made Christianity the official religion).
• Though his military reputation suffered from the Persian treaty, he is remembered as the emperor who brought back the faith of Constantine the Great.

Valentinian I (A.D. 364–375)
• Ruled the Western Roman Empire (Italy, Gaul, Britain, Spain, and Africa).
• A strong military leader, he fought off barbarian invasions (especially the Alemanni and Saxons).
• Though he was a Christian, he allowed religious tolerance and did not actively persecute pagans.
• Died from a stroke after an angry outburst during peace negotiations.

His Successors:
• Gratian (A.D. 375–383) – His son, who became emperor at just 16 years old.

• Valentinian II (A.D. 375–392) – His younger son, who ruled the Western Empire under the influence of powerful generals.
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2. Valens (A.D. 364–378)
• Ruled the Eastern Roman Empir
e (Greece, Egypt, Asia Minor, and the Middle East).
• Favored Arian Christianity, causing tensions with Nicene Christians.
• Died at the Battle of Adrianople (A.D. 378), where his army was crushed by the Goths. This battle marked the beginning of the end for the Western Roman Empire.
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3. Theodosius I (A.D. 379–395)
• Known as Theodosius the Great.

• Became the emperor of the Eastern Empire after Valens’ death.
• In A.D. 392, he united both East and West, becoming the last emperor to rule the whole Roman Empire.
• Made Christianity the official state religion in A.D. 380 (Edict of Thessalonica).
• Cracked down on paganism, closing temples and banning sacrifices.
• Died in A.D. 395, after which the empire was permanently split.
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After Theodosius: The Empire Splits for Good
Upon Theodosius' death in A.D. 395, his two sons took over:
Honorius (A.D. 395–423) – Ruled the Western Roman Empire (which fell in A.D. 476).
Arcadius (A.D. 395–408) – Ruled the Eastern Roman Empire (which became the Byzantine Empire).
This was the beginning of the end for Rome, as the West declined due to internal struggles and barbarian invasions, while the East (Byzantium) survived for another 1,000 years.

The Byzantine Empire (A.D. 330–1453)

Byzantine Empire was a Christian empire, and Christianity was at the heart of its identity, culture, and governance.

Byzantine Empire fell on May 29, 1453, when the Ottoman Turks, led by Sultan Mehmed II ("Mehmed the Conqueror"), captured Constantinople after a brutal siege. This event marked the end of the Eastern Roman (Byzantine) Empire and the rise of the Ottoman Empire 
The Ottomans, with an army of around 80,000–100,000 troops, surrounded the city.
The Byzantines, led by Emperor Constantine XI Palaiologos, had only 7,000–10,000 defenders, including some foreign allies (e.g., Genoese mercenaries).
Ottoman War Tactics

After 53 days of siege, the Ottomans launched a final massive attack.
Emperor Constantine XI fought bravely but was killed in battle, refusing to flee.

Mehmed II entered Hagia Sophia, which was converted into a mosque.
Constantinople became the new capital of the Ottoman Empire, later renamed Istanbul.
The fall of Byzantium Empire in 1453, which was the last remaining part of the Eastern Roman Empire and the rise of Islamic rule in the region.
Legacy of the Fall
Eastern Orthodox Christianity survived, with the Patriarch of Constantinople continuing under Ottoman rule.
Many Greek scholars fled to Western Europe, bringing knowledge that helped spark the Renaissance.

The fall of Constantinople symbolized the end of the Middle Ages and the beginning of the early modern era.

Though the empire fell, its Christian heritage, theological contributions, and Greek traditions lived on.