Slesin was formerly part of the German Empire. In the German Empire, the place was called Schlüsselsee.
The place is now called Ślesin and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Slesin | Russian Empire | Konin | 1914 |
| Ślesin | Poland | Konin | 1921 |
| Ślesin | German Empire | Konin | 1939 |
| Schlüsselsee | German Empire | Konin | 1939 |
| Ślesin | Poland | Konin | 1945 |
| Ślesin | Poland | Konin | 1992 |