Historical provinces of Finland
The historical provinces (Finnish: historialliset maakunnat, Swedish: historiska landskap) are former administrative or cultural areas of Finland, with origins from the slottslän (linnalääni) of the Middle Ages. The historical provinces ceased to be administrative entities in 1634 when they were superseded by the counties (lääni), a reform which remained in force in Finland until 1997.
Source: Wikipedia — Historical provinces of Finland (CC BY-SA 4.0)