Zadvajčen was formerly part of the German Empire. In the German Empire, the place was called Altkrug.
The place is now called Pervomajskoe and belongs to Russian Federation.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Sadweitschen | German Empire | Gumbinnen | 1938 |
| Altkrug | German Empire | Gumbinnen | 1939 |
| Zadvajčen | Under Soviet administration | Kaliningrad | 1945 |
| Pervomajskoe | Russian Federation | Gusev | 1992 |