Mazowsze was formerly part of the German Empire. In the German Empire, the place was called Massau.
The place is now called Mazowsze and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Mazowsze | Russian Empire | Lipno | 1914 |
| Mazowsze | Poland | Lipno | after the Versailles Treaty |
| Massau | German Empire | Leipe (Westpr.) | 1939 |
| Mazowsze | Poland | Lipno | 1945 |
| Mazowsze | Poland | Włocławek | 1992 |