Kolonja Słoszewo was formerly part of the German Empire. In the German Empire, the place was called Sloschewo Nowe.
The place is now called NN and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Kolonja Sloszewo | Russian Empire | Plonsk | 1914 |
| Kolonja Słoszewo | Poland | Płońsk | 1919 |
| Sloschewo Nowe | German Empire | Plöhnen | 1939 |
| Słoszewo Nowe | Poland | Płońsk | 1945 |
| NN | Poland | Ciechanów | 1992 |