| YEAR | DATE | EVENT | HEAD OF STATE |
| 1163 | Bishopland | ||
| 1254 | bishop John Drest | ||
| 1259 | x | ||
| 1586 | Bishop of Duchy of Holstein-Gottorp | ||
| 1596 | bishop Giovsanni Federico of Oldenburg arcibishop of Brema | ||
| 1634 | bishop John of Oldeburg | ||
| 1655 | x | ||
| 1666 | 4 july | bishop August Friedrich Herzog von Holstein-Gottorp | |
| 1705 | 2 october | bishop Christian August Herzog von Holstein-Gottorp | |
| 1726 | 25 april | bishop Karl August Herzog von Holstein-Gottorp | |
| 1727 | 16 september | bishop Adolf Friedrich Herzog von Holstein-Gottorp | |
| 1750 | 15 december | bishop Friedrich August Herzog von Holstein-Gottorp | |
| 1785 | 6 july | bishop Peter Friedrich Ludwig Herzog von Holstein-Gottorp | |
| 1803 | 4 july | Principality of greatduke of Oldenburg | |
| 1918 | Union to German State of Schleswig-Holstein |