Zagaj was formerly part of the German Empire. In the German Empire, the place was called Hinterholz.
The place is now called NN and belongs to Slovenia.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Sagaj | Austro-Hungary | Pettau/Ptuj | before the Treaty of Saint-Germain |
| Zagaj | Austro-Hungary | Pettau/Ptuj | before the Treaty of Saint-Germain |
| Zagaj | Yugoslavia | Šmarje | after the Treaty of Saint-Germain |
| Hinterholz | German Empire | Cilli | 1941 |
| Zagaj pod Bočem | Yugoslavia | Celje | 1945 |
| Zagaj pod Bočem | Yugoslavia | Socialistična rep. Slovenija | 1992 |
| NN | Slovenia | Slowenien | 1991 |