Hrastje was formerly part of the German Empire. In the German Empire, the place was called Hrastie.
The place is now called Hrastje and belongs to Slovenia.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Hrastje | Austro-Hungary | Krainburg/Kranj | before the Treaty of Saint-Germain |
| Hrastje | Yugoslavia | Kranj | after the Treaty of Saint-Germain |
| Hrastie | German Empire | Krainburg | 1941 |
| Hrastje | Yugoslavia | Kranj | 1945 |
| Hrastje | Yugoslavia | Socialistična rep. Slovenija | 1992 |
| Hrastje | Slovenia | Slowenien | 1991 |