Kossaken was formerly part of the German Empire. In the German Empire, the place was called Kossaken.
The place is now called Kosaki and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Kossaken | German Empire | Johannisburg | 1938 |
| Kosaki | Under Polish administration | Pisz | 1945 |
| Kosaki | Poland | Suwałki | 1992 |