traditional subdivision (province) of Sweden. The 25 landskap (provinces) developed during the pre-Viking and Viking eras and were independent political units with their own laws, judges, and councils. The division was based on geographical and cultural characteristics with which many people continue to identify. Although they no longer have any political or administrative significance, their names remain in common use and appear in official tabulations of data. The landskap overlap and occasionally coincide with the 26 län (counties) that came into being during the later European Middle Ages. The län were established in their modern form in the 17th and early 18th centuries, although through some consolidation their number was reduced to 21 by the end of the 20th century. Län still serve as Sweden's main administrative subdivisions.