The forces of Sverre attack the fleet of King Magnus on June 15, 1184, off the coast near the hamlet of Fimreite in the long and narrow Sognefjord in today's Sogndal municipality, Sogn og Fjordane county.
Magnus has several large ships, but none as huge as the Mariasuda, which Sverre has built.
Because of its great size, the seaworthiness of the Mariasuda is rather poor and it will only be useful within the narrow fjords.
The ships in the fleet of King Magnus are lashed together, creating the appearance of one big fleet.
While the Mariasuda holds up half of the enemy fleet, the rest attack the outlying enemy ships.
Sverre Sigurdsson sends his ships into battle in squadrons, to charge and overwhelm on one ship at a time, forcing Magnus's men to jump over to the next.
As the battle proceeds, the remaining ships become extremely crammed, then start to sink from the added weight.
King Magnus V is reported to have gone down with one of the last of them.
After Magnus' death, Sverre becomes the sole sovereign of Norway.
The civil war era in Norway does not end with this victory, however.
Sigurd Magnusson, Inge Magnusson and Erling Steinvegg will come forth eventually, all stating to be sons of Magnus and claiming the Norwegian throne.
