Kozjak was formerly part of the German Empire. In the German Empire, the place was called Ehrenstein.
The place is now called Kozjak and belongs to Slovenia.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Kosjak | Austro-Hungary | Windischgraz/Slovenji Gradec | before the Treaty of Saint-Germain |
| Kozjak | Austro-Hungary | Windischgraz/Slovenji Gradec | before the Treaty of Saint-Germain |
| Kozjak | Yugoslavia | Slovenj Gradec | after the Treaty of Saint-Germain |
| Ehrenstein | German Empire | Marburg an der Drau | 1941 |
| Kozjak | Yugoslavia | Maribor | 1945 |
| Kozjak | Yugoslavia | Socialistična rep. Slovenija | 1992 |
| Kozjak | Slovenia | Slowenien | 1991 |