Ljajssen was formerly part of the German Empire. In the German Empire, the place was called Leißen.
The place is now called Dolgorukovo * and belongs to Russian Federation.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Leißen | German Empire | Preußisch Eylau | 1939 |
| Ljajssen | Under Soviet administration | Kaliningrad | 1945 |
| Dolgorukovo * | Russian Federation | Bagrationovsk | 1992 |