Gaj was formerly part of the German Empire. In the German Empire, the place was called Gaj.
The place is now called Gaj and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Gaj | Austro-Hungary | Krenau/Chrzanów | before the Treaty of Saint-Germain |
| Gaj | Poland | Chrzanów | after the Treaty of Saint-Germain |
| Gaj | German Empire | Chrzanow/Krenau | 1939 |
| Gaj | Poland | Chrzanów | 1945 |
| Gaj | Poland | Katowice | 1992 |