Darkness was a constant companion of Man in ages past. One cannot overestimate how large a part of ordinary lives that were spent in the dark.
The lack of any effective and reliable source of artificial light meant that most labour and utilitarian work was constrained to the daylight hours and the non-winter months. It also meant that people were bound to their houses and cabins during large parts of the year, and that few ventured outside when darkness fell.
If one did go outside, one could be sure to come upon one of the Denizens of the Night, such as the 'lyktgubbe' (will-o'-wisp), whose alluring light would lead you astray from the path and into a bog or other danger. In all probability this spectral light was just the light of another person's torch or lantern, but in a land of total darkness the mind was quick to invent fanciful explanations for rather common phenomena.
Nowhere in Europe was the dark as total as in Scandinavia, where the sun is hardly to be seen for a good part of the year. This has given rise to a rich tradition of myth and folklore, with a great many representations of supernatural beings prowling the shadows of the night.