Decades: 370s BC 360s BC 350s BC 340s BC 330s BC - **320s BC** - 310s BC 300s BC 290s BC 280s BC 270s BC

326 BC 325 BC 324 BC 323 BC 322 BC - **321 BC** - 320 BC 319 BC 318 BC 317 BC 316 BC

- Battle of the Claudine Forks, the Romans under Spurius Postumius and T. Verturius Calvinus are defeated by the Samnites under Gaius Pontius.

- Perdiccas, regent of Macedonia (assassination)
- Zhou Xian Wang, King of the Zhou Dynasty of China.