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