| YEAR | DATE | EVENT | HEAD OF STATE |
| .... | Bishopland | ||
| 1205 | Bishop Iso Wolpe | ||
| 1231 | x | ||
| 1241 | Bishop Burcardo of Oldenburg | ||
| 1251 | bishop Gerardo Hoya | ||
| 1269 | Bishop Corrado of Brunswick | ||
| 1300 | x | ||
| 1388 | Bishop Ottone of Brunswick | ||
| 1406 | x | ||
| 1419 | Bishop Ludovico of Sundgau | ||
| 1431 | x | ||
| 1502 | Bishop Cristoforo of Brunswick | ||
| 1548 | Bishop Giorgio of Brunswick | ||
| 1558 | x | ||
| 1586 | Bishop Filippo Sigismondo of Brunswick | ||
| 1623 | x | ||
| 1648 | Duchy of King of Sweden | ||
| 1711 | Union to Duchy of Lauenburg |