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