Dłużec was formerly part of the German Empire. In the German Empire, the place was called Langbrück.
The place is now called Dłużec and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Langbrück | German Empire | Angerburg | 1939 |
| Dłużec | Under Polish administration | Węgorzewo | 1945 |
| Dłużec | Poland | Suwałki | 1992 |