Ossegg was formerly part of the German Empire. In the German Empire, the place was called Ossek.
The place is now called Osek and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Ossegg | Austro-Hungary | Dux | before the Treaty of Saint-Germain |
| Osek | Austro-Hungary | Dux | before the Treaty of Saint-Germain |
| Osek | Czechoslovakia | Duchcov | after the Treaty of Saint-Germain |
| Ossek | Czechoslovakia | Duchcov | after the Treaty of Saint-Germain |
| Ossegg | German Empire | Dux | 1938 |
| Ossek | German Empire | Dux | 1938 |
| Osek | Czechoslovakia | Duchcov | 1945 |
| Osek | Czechoslovakia | Teplice | 1992 |
| Osek | Czech Republic | Teplice | 1993 |