Sienno was formerly part of the German Empire. In the German Empire, the place was called Justhöfen.
The place is now called Sienno and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Sienno | German Empire | Bromberg | before the Versailles Treaty |
| Sienno | Poland | Bydgoszcz | after the Versailles Treaty |
| Justhöfen | German Empire | Bromberg | 1939 |
| Sienno | Poland | Bydgoszcz | 1945 |
| Sienno | Poland | Bydgoszcz | 1992 |