Haj was formerly part of the German Empire. In the German Empire, the place was called Háje.
The place is now called Háje and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Haj | Austro-Hungary | Přestitz | before the Treaty of Saint-Germain |
| Háje | Austro-Hungary | Přestitz | before the Treaty of Saint-Germain |
| Háje | Czechoslovakia | Přeštice | after the Treaty of Saint-Germain |
| Hag | German Empire | Pschestitz | 1939 |
| Háje | German Empire | Pschestitz | 1939 |
| Háje | Czechoslovakia | Přeštice | 1945 |
| Háje | Czechoslovakia | Plzeň-jih | 1992 |
| Háje | Czech Republic | Plzeň-jih | 1993 |