Bladiau was formerly part of the German Empire. In the German Empire, the place was called Bladiau.
The place is now called Pjatidorožnoe and belongs to Russian Federation.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Bladiau | German Empire | Heiligenbeil | 1939 |
| Bladiau | Under Soviet administration | Kaliningrad | 1945 |
| Pjatidorožnoe | Russian Federation | Bagrationovsk | 1992 |