Klein Reußen was formerly part of the German Empire. In the German Empire, the place was called Klein Reußen.
The place is now called Ruś Mała and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Klein Reußen | German Empire | Osterode i. Ostpr. | 1939 |
| Ruś Mała | Under Polish administration | Ostróda | 1945 |
| Ruś Mała | Poland | Olsztyn | 1992 |