The Great Plague or The Black Death in the 14th and 15th century Europe still puzzles science. A long lived theory blamed the black rat but later research might alter this view. Queen Margrete I took power after her father, Valdemar. He had been forced to give up castles and estates in Skåne for a longer period of time to the Hansa - a league of free German cities. Margrete ́s goal was always to win it all back.