320 CE

Pappus of Alexandria, Greek philosopher, observes an eclipse of the sun and writes a commentary on The Great Astronomer (Almagest). King Chandragupta I founds the Gupta dynasty in northern India (approximate date). In Nydam Mose (Denmark), the Nydam oak boat is sacrificed by the Danes (the boat is excavated in the 1830s, when a local farmer finds weapons, including swords and spears).

In the 320s, the 4th century.

Geopolitics & Diplomacy

  • Crispus, eldest son of Constantine I, leads a victorious campaign against the Franks, assuring twenty years of peace along the Rhine frontier. He establishes his residence in Augusta Treverorum (modern Trier), capital of Germania.source

Exploration & Expansion

  • King Chandragupta I founds the Gupta dynasty in northern India (approximate date).source
  • In Nydam Mose (Denmark), the Nydam oak boat is sacrificed by the Danes (the boat is excavated in the 1830s, when a local farmer finds weapons, including swords and spears).source

Religion & Belief

  • Licinius reneges on the religious freedom promised by the Edict of Milan, and begins a new persecution of Christians in the Eastern Roman Empire. He imprisons Christians, confiscates their properties and destroys churches.source

Science & Discovery

  • October 18 – Pappus of Alexandria, Greek philosopher, observes an eclipse of the sun and writes a commentary on The Great Astronomer (Almagest).source

Culture & Society

  • Construction begins on the Old St. Peter's Basilica, Rome (approximate date).source

Births

  • Flavian I, Patriarch of Antioch (died 404)source
  • Constans I, Roman emperor (died 350)source
  • Oribasius, Greek physician (approximate date)source
  • Tuoba Shiyiqian, prince of the Tuoba Dai (died 376)source
  • Aurelius Victor, Roman historian and politician (approximate date)source
  • Jin Jianwendi, emperor of the Jin Dynasty (died 372)source
  • Xie An, statesman of the Jin Dynasty (died 385)source

Deaths

  • January 2 – Narcissus, Argeus, and Marcellinus, Roman Catholic martyrs and saintssource
  • January 29 – Valerius of Trèves, Roman Catholic priest and saintsource
  • February 6 – Dorothea of Alexandria, Roman Catholic virgin, martyr and saintsource
  • March 9 – 40 Martyrs of Sebastesource
  • March 10 – Cyrion and Candidus, Armenian Orthodox priest and saintssource
  • July 11 – Januarius and Pelagia, Roman Catholic priests, martyrs and saintssource
  • November 29 – Saint Illuminata, Roman Catholic religious sister and saintsource
  • December 9 – Proculus of Verona, Roman Catholic priest and saintsource
  • Sima Bao, prince of the Jin Dynasty (born 294)source
  • Zhang Shi (張寔), Zhang Duke of Xiping and governor of Liang Province, (涼州)is assassinated by Yan She (閻涉) and Zhao Ang (趙卬) and replaced by Zhang Mao (張茂), commonly accepted first ruler of the Chinese state Former Liang.source
  • Lactantius, Christian writer (approximate date)source