Białężyn was formerly part of the German Empire. In the German Empire, the place was called Belsin.
The place is now called Białężyn and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Belsin | German Empire | Czarnikau | before the Versailles Treaty |
| Białężyn | Poland | Czarnków | after the Versailles Treaty |
| Belsin | German Empire | Scharnikau (Wartheland) | 1939 |
| Białężyn | Poland | Czarnków | 1945 |
| Białężyn | Poland | Piła | 1992 |