364 BC

By place

Greece

• On the advice of the city's military leader, Epaminondas, Thebes builds a fleet of 100 triremes to help combat Athens. Thebes destroys its Boeotian rival Orchomenus.
• Philip II of Macedon, brother of the reigning king of Macedonia, returns to his native land after having been held as a hostage in Thebes since 369 BC.
• The army of Thebes under their statesman and general, Pelopidas, defeats Alexander of Pherae in the Battle of Cynoscephalae in Thessaly, but Pelopidas is killed during the battle. As a result of his loss of this battle, Alexander is compelled by Thebes to acknowledge the freedom of the Thessalian cities, to limit his rule to Pherae, and to join the Boeotian League.
• The Spartans under Archidamus III are defeated by the Arcadians at Cromnus.
• The Athenian general, Iphicrates, fails in attempts to recover Amphipolis. Retiring to Thrace, Iphicrates fights for his father-in-law, the Thracian king Cotys I, against Athens for the possession of the Thracian Chersonese. Cotys I is victorious and controls the whole Chersonese peninsula.
• Timophanes, along with a number of colleagues, including his brother Timoleon, takes possession of the acropolis of Corinth and Timophanes makes himself master of the city. Later, Timoleon, after ineffectual protests, tacitly acquiesces to his colleagues putting Timophanes to death for his actions.

  China

• The Chinese astronomer Gan De from the State of Qi reportedly discovers the moon Ganymede, belonging to Jupiter, and makes the earliest known sunspot observations.