German settlers and prisoners of war vigorously colonised inhabited areas between the 12th and 14th centuries. The growth of the native Wielopolska population between the 15th and 17th centuries led these settlements to expand outwards and cultivate areas that had once been forests. This in turn shifted the boundary of the Wielkopolska population. New settlers moved into the area during the 17th, 18th and early 19th centuries and appropriated the remaining swampy and forested land. These settlement waves are referred to as German, or as we say in the countryside, “Olęder”. The name comes from “Holland”, where this system of settlement began before spreading to Prussia and Poland. Traces of this settlement are still visible in the distinctive countryside around Nowy Tomyśl.