Lessen (Westpr.) was formerly part of the German Empire. In the German Empire, the place was called Lessen, Kr. Graudenz.
The place is now called Łasin and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Lessen (Westpr.) | German Empire | Graudenz | before the Versailles Treaty |
| Łasin | Poland | Grudziądz | after the Versailles Treaty |
| Lessen, Kr. Graudenz | German Empire | Graudenz | 1939 |
| Łasin | Poland | Grudziądz | 1945 |
| Łasin | Poland | Toruń | 1992 |