The Battle of Hjörungavágr is a semi-legendary naval battle that took place in the late 10th century between the Jarls of Lade and a Danish invasion fleet led by the fabled Jomsvikings. This battle played an important role in the struggle by Haakon Sigurdsson to unite his rule over Norway
Haakon Sigurdsson ruled Norway as a vassal of King Harald Bluetooth of Denmark
, but he was in reality an independent ruler. Haakon was a strong believer in the old Norse gods.When Harald Bluetooth attempted to force Christianity upon him around 975, Haakon broke his allegiance to Denmark.