Firlej was formerly part of the German Empire. In the German Empire, the place was called Firlej.
The place is now called Firlej and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Firlej | Russian Empire | Petrokov | 1914 |
| Firlej | Poland | Piotrków | 1921 |
| Firlej | German Empire | Lask | 1939 |
| Firlej | Poland | Bełchatów | 1945 |
| Firlej | Poland | Piotrków | 1992 |