Constantine the great; Founder of Constantinople

Constantine the great

Reign: 306–337 AD

Parents: Constantius & Helena

Born: 275 AD, Naissus (modern-day Niš, Serbia)

Died : 337 AD, Constantinople

A Time of Chaos The 3rd century AD

A Time of Chaos

The 3rd century was a turbulent period for the Roman Empire.

Between 230 and 284 AD, the empire faced continuous civil wars, invasions, and economic collapse. Generals frequently seized power, only to be killed shortly afterward.

In 284, Diocletian became emperor and recognized that the empire was too vast to be ruled by a single man. To restore stability, he introduced the Tetrarchy in 293—a system dividing imperial power among four rulers:

Senior Emperors (Augusti):

• Diocletian – East (based in Split, Croatia)

• Maximian – West (based in Milan)

  
  

Junior Emperors (Caesars, designated successors):

• Galerius – under Diocletian (based in Nicomedia)

• Constantius – under Maximian (Gaul, Spain, Britain)

  
  

This system brought about roughly 12 years of relative peace.

Constantine..sole emperor in 311 AD

Rise of Constantine

In 305, Diocletian retired and passed his throne to his son Galerius.

Constantius died in 306, his son Constantine, aged 30, was declared his successor.

Constantine, previously held as a hostage in Nicomedia to ensure his father’s loyalty, immediately moved to Britain and became Augustus, ruling Britain, Gaul, and Spain.

Meanwhile, Maxentius, son of retired emperor Maximian, declared himself emperor in Rome in 306.

To strengthen his position, Constantine married Fausta, Maximian’s daughter, in 307.

Two years later, Constantine defeated and killed Maxentius and also Maximian at the Battle of Milvian Bridge, consolidating his power.

By 310, the empire had four emperors:

1. Galerius – East (Nicomedia)

2. Maxentius – Italy

3. Constantine – Gaul, Spain, Britain

4. Domitius – Africa (usurper)

Galerius died in 311, and Constantine became the central figure in Roman politics.

Edict of Milan

Champion of Christianity

In 313, Constantine issued the Edict of Milan, granting full religious freedom throughout the Roman Empire and ending the official persecution of Christians.

He also convened the First Ecumenical Council of Nicaea in 325 (modern-day İznik, Turkey), which:

• Unified Christian doctrine

• Condemned Arianism (the belief that Jesus was a created being)

• Affirmed that Jesus Christ was eternal, uncreated, and fully divine

Constantine on the right

Founder of Constantinople

In 330, Constantine established Constantinople (modern-day Istanbul) as the new capital of the Roman Empire, ruling as its sole master of the Western Empire by 324, and later over the Eastern Empire, until his death in 337.