Decades: 460s BC 450s BC 440s BC 430s BC 420s BC - **410s BC** - 400s BC 390s BC 380s BC 370s BC 360s BC

Years: 423 BC 422 BC 421 BC 420 BC 419 BC - **418 BC** - 417 BC 416 BC 415 BC 414 BC 413 BC

- Battle of Mantinea - The Spartans led by Agis II defeat the Argives, Mantineans, and Athenians, the largest land battle of the Peloponnesian War

- Epaminondas of Thebes
- Iphicrates (approximate date)