One historical theory I read was that a lot of the negative stories about vikings were put about by disgruntled Britons who were unhappy because a lot of British women preferred to marry viking men because they used to wash once a week whereas the standard behaviour for British men was to wash once a year.

  > A later writing often credited to the Abbot of St. Albans   
  > reports that "thanks to their habit of combing their hair
  > every day, of bathing every Saturday and regularly 
  > changing their clothes, were able to undermine the virtue   
  > of married women and even seduce the daughters of nobles 
  > to be their mistresses."

https://www.danishnet.com/vikings/cleanliness-did-vikings-ta...