LANGUAGE
In 1066 C.E., when the Norman conquest brought an end to the Viking Age, all effects of Danish influence were removed and replaced by English culture save for one: the effect of the Norse language on the development of the English language.
berserk = berserker
Have you or anyone you know ever gone ‘berserk’? Viking leaders sent warriors carrying no weaponry and dressed only in bear shirts to surprise the targets of their attacks through shock and awe. These Viking “bear shirt wearers” or berserkers, as they were called in Old Norse, were instrumental in setting the stage for a successful raid (Kane 113).
Many English words of violence have their roots in Old Norse.
Apparently, these violent behaviors were satisfying to the Vikings because they also gave us our word for happy (happ) (Kane 84).