Siadcza was formerly part of the German Empire. In the German Empire, the place was called Eichenbaum.
The place is now called Siadcza and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Sedschin | German Empire | Grünberg i. Schles. | 1937 |
| Sedczyn | German Empire | Grünberg i. Schles. | 1937 |
| Eichenbaum | German Empire | Grünberg i. Schles. | 1939 |
| Siadcza | Under Polish administration | Sulechów | 1945 |
| Siadcza | Poland | Zielona Góra | 1992 |