It was a conflict between two royal families over hereditary demands and special interests and was triggered by the murder of Eric V of Denmark.

The murder of Eric V of Denmark in Findrup in 1286 had political consequences for the Danish nobles who had been in opposition[clarification needed].

King Erik II's first war expedition with the outlaws, a fleet called the Leidgang, sailed into the Øresund on the night of 6 July 1289.

On Saturday, 9 July, Ven and Amager were burned but at the Battle of Skanör, the Norwegian chieftain Thord Krytter fell with 70 men and the town was not destroyed.

After an unsuccessful peace agreement, the Leidgang fleet sailed south of Møn to Grønsund and landed.

King Erik II undertook other war expeditions with the outlaws, and probably also with his brother Duke Haakon.

The princes promised that they would not help the Norwegian king for two years, allow his forces to go through their country, or permit their subjects to go serve him.

In return, King Erik Menved promised the princes a considerable amount of money.