The sea battle of Nesjar in 1016 was fought to determine rulership of this country.
Sweden
Norway
Denmark
The Netherlands
Norway. After Olaf Haraldsson, also known as Olaf II and St. Olaf, proclaimed himself ruler of Norway, Sveinn Hakonarson, ruler of the Swedish part of Norway, sailed with a force to confront him. Few accounts exist of the Battle of Nesjar, but it ended with Sveinn retreating to Sweden.