400
- For alternate uses, see Number 400.
| Years: 396 397 398 399 - 400 - 401 402 403 404 | |
| Decades: 370s 380s 390s - 400s - 410s 420s 430s | |
| Centuries: 3rd century - 4th century - 5th century | |
Events
- First invasion of Italy by Alaric (probable date).
- The Vandals start their westward trek from Dacia and Hungary (approximate date).
- Construction (and therefore occupation) at Great Zimbabwe begins (approximate date).
- Earliest date of human occupation on Easter Island (approximate date).
- Chrysanthemums are introduced to Japan (approximate date).