Soldau was formerly part of the German Empire. In the German Empire, the place was called Soldau.
The place is now called Działdowo and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Soldau (Ostpr.) | German Empire | Neidenburg | before the Versailles Treaty |
| Działdowo | Poland | Działdowo | after the Versailles Treaty |
| Soldau | German Empire | Neidenburg | 1939 |
| Działdowo | Poland | Działdowo | 1945 |
| Działdowo | Poland | Ciechanów | 1992 |