In 1935 the local historian Albert Breyer from Sompolno published an article in the periodical "Ostdeutsche Heimathefte". The article was headed "Deutsche Gaue in Mittelpolen" and contained a map showing the origin of German settlers in Central Poland.
By travelling through Central Poland Albert Breyer realized that there seemed to be a connection between the geographical structure of the regions and the origin of the ethnic Germans living there. This can be explained by the different settlement waves that brought people from different areas and for different reasons to Central Poland.
This map is still a valuable source for people researching their German ancestors in Central Poland.
In the digital reproduction of the Breyer Map the hatching has been replaced by colors to make interpretation easier.
Albert Breyer - Landschaftliche Gliederung des Deutschtums in Mittelpolen
Source: Breyer, Albert - Deutsche Gaue in Mittelpolen