401 BCCenturies: 6th century BC - 5th century BC - 4th century BC
- Agesilaus II becomes king of Sparta
- Battle of Cunaxa: Cyrus the Younger revolts against Artaxerxes II of Persia with help of ten thousand Greek mercenaries, but is defeated. Xenophon leads the surviving Greeks in a retreat home.
- Zhou an wang becomes King of the Zhou Dynasty of China.