Kopanica was formerly part of the German Empire. In the German Empire, the place was called Mittelmühlen.
The place is now called Kopanica and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Kopnitz | German Empire | Bomst | before the Versailles Treaty |
| Kopanica | Poland | Wolsztyn | after the Versailles Treaty |
| Kopnitz | German Empire | Wollstein | 1939 |
| Mittelmühlen | German Empire | Wollstein | 1939 |
| Kopanica | Poland | Wolsztyn | 1945 |
| Kopanica | Poland | Zielona Góra | 1992 |