| 390 B.C. | Defeat of Rome by the Gauls halts Roman expansion. |
| 380 B.C. | Death of comic playwright Aristophanes. |
| 367 B.C. | Rule by consulship established in Rome. Death of Dionysius I, tyrant of Syracuse, and subsequent brief return of Plato to Sicily. |
| 361–360 B.C. | Plato’s third trip to Sicily. |
| 353 B.C. | Death of King Mausolus, who is buried in the Mausoleum, one of the Seven Wonders of the ancient world. |
| 348 B.C. | Second treaty between Rome and Carthage. |
| 347 B.C. | Death of Plato. |
| 335 B.C. | Alexander the Great succeeds his father, Philip II, and sets out on his career of conquest. |
| 326 B.C. | Alexander the Great reaches the gateway to India, his empire stretching at its farthest limit from the Adriatic to beyond the Indus. |
| 323 B.C. | Death of Alexander the Great and ensuing breakup of his empire. |