Bardyllis becomes king of Illyria and the Dardani and establishes the Bardyllian Dynasty. Jason of Pherae becomes tyrant of Thessaly. Plato forms his Academy, teaching mathematics, astronomy and other sciences as well as philosophy. It is dedicated to the Attic hero Academus. Philanthropists bear all costs; students pay no fees.
Geopolitics & Diplomacy
Bardyllis becomes king of Illyria and the Dardani and establishes the Bardyllian Dynasty.source
Conflict & Security
Mantinea gets destroyed by Sparta and their subdued thebans allies.source
Democritus announces that the Milky Way is composed of many stars.source
Plato forms his Academy, teaching mathematics, astronomy and other sciences as well as philosophy. It is dedicated to the Attic hero Academus. Philanthropists bear all costs; students pay no fees.source
Culture & Society
Dionysius I of Syracuse attempts to restore Alcetas I of Epirus to the throne.source
Births
Mentor of Rhodes, Greek mercenary and satrap (approximate date)source
Deaths
Chuzi II, Chinese ruler of the Zhou Dynasty (approximate date)source