| YEAR | DATE | EVENT | HEAD OF STATE |
| 1101 | Count - dinasty Diez | earl Enrico I | |
| 1117 | earl Gerardo I | ||
| 1133 | earl Embricho | ||
| 1166 | earl Enrico II | ||
| 1189 | earl Gerardo II | ||
| 1228 | earl Enrico III | ||
| 1230 | earl Gerardo III | ||
| 1266 | earl Gerardo IV | ||
| 1306 | earl Gerardo V | ||
| 1307 | earl Gerardo VI | ||
| 1343 | earl Gerardo VII | ||
| 1386 | Count of Nassau-Diez - dinasty Nassau | earl Adolfo | |
| 1420 | earl John II | ||
| 1443 | earl John IV | ||
| 1475 | earl Engelberto II | ||
| 1504 | earl Guglielmo I | ||
| 1559 | earl John VI | ||
| 1605 | earl Ernesto Casimiro | ||
| 1632 | earl Enrico Casimiro I | ||
| 1640 | earl Guglielmo Federico | ||
| 1654 | Principality | prince Guglielmo Federico | |
| 1664 | prince Enrico Casimiro II | ||
| 1696 | prince John Guglielmo Friso | ||
| 1711 | prince Guglielmo IV | ||
| 1751 | prince Guglielmo V | ||
| 1802 | Union to Landgraft of Hesse | ||
| 1918 | 9 november | Union to German State of Westfalia |