According to Saxo Grammaticus, both hosts prepared for seven years, and mustered armies of 200 000 men. Harald was joined by the legendary heroes Ubbe of Friesland, Uvle Brede, Are the One-eyed, Dag the Fat, Duk the Slav, Hroi Whitebeard and Hothbrodd the Indomitable as well as 300 shieldmaidens led by Hed, Visna of the Slavs and Hedborg. Sigurd recruited the legendary heroes Starkad, Egil the Bald, Grette the Evil, Blig Bignose, Einar the Fatbellied and Erling Snake. Famous Swedes were Arwakki, Keklu-Karl, Krok the peasant, Gummi and Gudfast from Gislamark. They were joined by scores of Norwegians, Slavs, Finns, Estonians, Curonians, Bjarmians, Livonians, Saxons, Angles, Frisians, Irish, Rus' etc... All picking their sides. Whole forests were chopped down in order to build 3000 longships to transport the Swedes. Harald's Danes had built so many ships that they could walk across The Sound. The numbers are obviously exaggerated, certainly tenfold or more. For comparison with the 3000 Swedish ships, the leidang fleets of the Scandinavian kingdoms numbered around 300 ships each during the Viking Age.
Location
The Hervarar saga ok Heiðreks speaks of "Brávelli í eystra Gautlandi" and in Sǫgubrot af nokkrum fornkonungum the battle is said to have taken place south of Kolmården, which separated Svealand from East Götaland and is where Bråviken is located: "Kolmerkr, er skilr Svíþjóð ok Eystra-Gautland... sem heitir Brávík". Saxo ends his account by saying "thus ended the battle of Bråvik". Most historians have held the battle to have taken place near Bråviken, but in the 17th century a minority view appears to have located it in Småland at Lake Åsnen.
Battle
The accounts found in Gesta Danorum and the Sǫgubrot saga are essentially the same. At first the two armies fought collectively, but after a while Ubbi was in the centre of attention. He slew first Ragnvald the Wise Councilor, then the champion Tryggvi and three Swedish princes of the royal dynasty. Humbled, King Sigurd Hring sent forth the champion Starkad, who managed to wound Ubbi but was himself even more seriously wounded. Then Ubbi killed Agnar, and took the sword in both hands and slashed a path through the Swedish host, until he fell riddled with arrows from the archers of Telemark. Then the shieldmaidenVeborg killed the champion Soti and managed to give additional wounds to Starkad, who was greatly angered. She was killed by the champion Thorkell. Furious, Starkad went forth in the Danish army, killing warriors all around him, and cut off the shieldmaiden Visna's arm, which held the Danish banner. Starkad then proceeded to slay the champions Brai, Grepi, Gamli and Haki. When Harald had observed these heroic feats, he stood on his knees in his chariot with one sword in each hand and killed a great many warriors both to his left and to his right. After a while, Harald's steward Bruni deemed that his liege had amassed enough glory and crushed the king's skull with a club.
Outcome
Sigurd won the battle and became the sovereign ruler of all of Sweden and Denmark.
Historicity
The general agreement on the historicity of the battle has turned back and forth during the last two centuries depending on what was the prevalent ideology among Scandinavian historians. In 1925, the Swedish archaeologist Birger Nerman summarized the ebbs and tides of its historicity. He stated that older scholarship had treated the accounts of the battle uncritically and perceived the accounts as largely historical. During the last decades of the 19th century, however, the hypercritical school considered the battle as entirely fictional and considered even the area where it took place as mythical. The pendulum turned and during the first decades of the 20th century, the opinion was once again in favour of its historicity, although the contemporary scholarship regarded it as a fictionalized historic event. In 1990, the Swedish encyclopedia Nationalencyklopedin summed up the debate by claiming that the historicity of the battle is impossible to verify. There is also a hypothesis relating the battle to the events of 827 when Harald Klak was expelled from Denmark.