Dlouhý was formerly part of the German Empire. In the German Empire, the place was called Dlouhý.
The place is now called Dlouhý and belongs to Czechoslovakia.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Dluhey | Austro-Hungary | Semil | before the Treaty of Saint-Germain |
| Dluhý | Austro-Hungary | Semil | before the Treaty of Saint-Germain |
| Dlouhý | Czechoslovakia | Semily | after the Treaty of Saint-Germain |
| Dlouhy | German Empire | Semil | 1939 |
| Dlouhý | German Empire | Semil | 1939 |
| Dlouhý | Czechoslovakia | Semily | 1945 |
| Dlouhý | Czechoslovakia | Východní Čechy | 1992 |