Księżno was formerly part of the German Empire. In the German Empire, the place was called Fürstenau.
The place is now called Księżno and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Fürstenau | German Empire | Rößel | 1939 |
| Księżno | Under Polish administration | Reszel | 1945 |
| Księżno | Poland | Olsztyn | 1992 |