| YEAR | DATE | EVENT | HEAD OF STATE |
| 1289 | Duchy - dinasty Brunswick-Este | duke Enrico I | |
| 1322 | duke Enrico II | ||
| 1351 | duke Ottone I king of Napoli | ||
| 1399 | duke Erik I | ||
| 1427 | duke Enrico III | ||
| 1464 | duke Enrico IV | ||
| 1526 | duke Filippo I | ||
| 1551 | duke Ernesto | ||
| 1567 | duke Wolfgang | ||
| 1595 | duke Filippo II | ||
| 1596 | duke Enrico Giulio | ||
| 1613 | duke Federico Ulrico | ||
| 1617 | Duchy of Duchy of Brunswick-Luneburg | ||
| 1665 | dinasty Brunswick-Este | duke John Federico | |
| 1679 | duke Ernesto Augusto p.e. of Hannover | ||
| 1698 | Union to Principality Electoral of Hannover |