Rosenau was formerly part of the German Empire. In the German Empire, the place was called Kulmischrosenau.
The place is now called Różnowo and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Rosenau | German Empire | Kulm | before the Versailles Treaty |
| Różnowo | Poland | Chełmno | after the Versailles Treaty |
| Kulmischrosenau | German Empire | Kulm (Weichsel) | 1939 |
| Różnowo | Poland | Chełmno | 1945 |
| Różnowo | Poland | Toruń | 1992 |