Kozielec was formerly part of the German Empire. In the German Empire, the place was called Jagowshöhe.
The place is now called Kozielec and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Kozielec | German Empire | Marienwerder | before the Versailles Treaty |
| Kozielec | Poland | Gniew | after the Versailles Treaty |
| Jagowshöhe | German Empire | Schwetz (Weichsel) | 1939 |
| Kozielec | Poland | Świecie | 1945 |
| Kozielec | Poland | Bydgoszcz | 1992 |