Battle of Nesjar
1016 CE.
Shown on the map at 58.992°, 9.827°.
Battle of Nesjar (Slaget ved Nesjar) was a sea battle off the coast of Norway in 1016. It was a primary event in the reign of King Olav Haraldsson (later Saint Olav). Icelandic skald and court poet Sigvatr Þórðarson composed the poem Nesjavísur in memory of the battle. A monument known as the Nesjar Monument was erected on the 1000th anniversary of the battle, located in Helgeroa village in Larvik, Vestfold County, where the battle is believed to have occurred.
Text from the Wikipedia article Battle of Nesjar, licensed CC BY-SA 4.0.