Blanschen was formerly part of the German Empire. In the German Empire, the place was called NN.
The place is now called Planchet and belongs to France.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Blanschen | German Empire | Thann | before the Versailles Treaty |
| Blanchen | France | Haut-Rhin | after the Versailles Treaty |
| NN | German Empire | Tann | 1940 |
| Planchet | France | Haut-Rhin | 1945 |
| Planchet | France | Haut-Rhin | 1993 |