| YEAR | DATE | EVENT | HEAD OF STATE |
| 1490 | Duchy - dinasty Oldenburg | duke Federico I Re of Danmark | |
| 1533 | duke Cristiano III Re of Danmark | ||
| 1544 | duke Adolfo | ||
| 1586 | duke Federico II | ||
| 1587 | duke Filippo | ||
| 1590 | duke John Adolfo | ||
| 1616 | duke Federico III | ||
| 1659 | duke Cristiano Alberto | ||
| 1695 | duke Federico IV | ||
| 1702 | duke Carlo Federico | ||
| 1739 | duke Pietro III Zar of Russia | ||
| 1762 | duke Paolo I Zar of Russia | ||
| 1773 | Union to Duchy of Schleswig |