4th century

As a means of recording the passage of time, the 4th century (per the Julian/Gregorian calendar and anno Domini era) was that century which lasted from 301 to 400.

Overview

The early part of the century was shaped by Constantine I, who is notable for moving the imperial capital from Rome to Byzantium (soon renamed Constantinople in honor of it's founder), and his conversion to Christianity - the first Roman Emperor to do so. Constantine was also the last emperor to control both the eastern and western halves of the empire. As the century progressed after his death, the two emperor system originally established by Diocletian in the previous century fell into regular practice. The Roman empire continued to prosper throughout this period, but suffered from AD376 onward from recurring invasions by Germanic tribes. These early invasions marked the beginning of the end for the Western Roman Empire.

Events

Contemporary bronze head of Constantine I.

• 301: Armenia first to adopt Christianity as state religion
• 306–337: Constantine I, ends persecution of Christians in the Roman Empire, calls First Council of Nicaea, see also Constantinian shift, Constantinople becomes new seat of government (New Rome)
• 378: Battle of Adrianople
• 378–395: Theodosius I, Roman emperor, bans pagan worship, Christianity is made the official religion of the Empire.
• 383: Battle of Fei River in China

Significant people

• Arius, founder of Arianism
• Athanasius, opponent of Arius
• Saint Augustine of Hippo, theologian
• Saint Ambrose, bishop of Milan
• Basil of Caesarea, reformer of Christian monasticism
• Julian the Apostate
• Eusebius, famous Christian Church historian
• Frumentius, Apostle of Ethiopia
• Ge Hong, Chinese alchemist
• Ammianus Marcellinus, Roman Historian
• Saint Martin of Tours
• Pachomius, founder of Christian monasticism
• Ulfilas, apostle of the Goths
• Gwanggaeto the Great of Goguryeo, King of ancient Korean state Goguryeo who greatly expanded its territory

Inventions, discoveries, introductions

• Kama Sutra
• Codex Sinaiticus, Codex Vaticanus, earliest Christian bibles
• Book of Steps, Syriac religious discourses