Seifershau was formerly part of the German Empire. In the German Empire, the place was called Seifershau.
The place is now called Kopaniec and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Seifershau | German Empire | Hirschberg i. Rsgb. | 1939 |
| Kopaniec | Under Polish administration | Jelenia Góra | 1945 |
| Kopaniec | Poland | Jelenia Góra | 1992 |