[2] Harald Wartooth is stated by most texts to have flourished three generations before the conquest of part of England by the sons of Ragnar Lodbrok (860s-870s).
The most detailed text is Saxo Grammaticus's chronicle Gesta Danorum (c. 1200) which is however complicated by the flow of Danish-patriotic rhetoric, in part a reflection of the Valdemarian age of military expansion.
An Icelandic text Sögubrot af nokkrum fornkonungum (Fragment of a saga about some ancient kings, 13th century) provides brief details about his life and a fuller account of his dramatic demise.
[4] A lay about the Bråvalla battle, seemingly written by a Norwegian skald in the 11th century, may once have existed, forming the basis for the extended saga accounts.
According to Sögubrot, Njal's Saga and the Lay of Hyndla, Harald was the son of Hrœrekr Ringslinger (slöngvanbaugi), the king of Zealand.
[13] According to Sögubrot, his mother Auðr fled to Garðaríki with her young son when her husband King Hrœrekr was treacherously killed in Zealand by his father-in-law Ivar Vidfamne.
When his grandfather Ivar drowned during a punitive expedition against Raðbarðr, young Harald traveled to Zealand, where he was accepted as king.
[14] Hervarar saga also mentions that Harald retook his grandfather's domains, but it says that the conquests started out from Götaland (or Gotland depending on the manuscript).
The Hervarar saga also alleges that Harald's nephew Sigurd Hring became (subservient) king over Denmark, which is gainsaid by other sources.
Later on he murdered Veseti on the latter's wedding night in Scania, and proceeded in slaying King Hader of Jutland and two further petty rulers called Hunding and Rørik, seizing the traditional royal center in Lejre.
[17] When the Norwegian petty ruler Åsmund was deposed by his own sister, Harald intervened with a single ship to remedy this infamy.
Unarmed and clad in a purple cloak and gold-embroidered coif, he strode towards the enemy at the head of his troops, while the adversaries vainly showered him with javelins.
Before battle had been joined, Odin appeared before Harald and gave him valuable advice about military tactics, especially the wedge-like Svinfylking formation.
[19] When Ingjald passed away at a later time, his adolescent son Hring inherited him, while Harald appointed suitable guardians for the boy.
[20] A new incident in Norway draw Harald's attention, as King Olaf of the Thrøndir was attacked by the shield-maidens Stikla and Rusla.
When Brune drowned on a journey, Odin, who had by now abandoned Harald's cause, took his likeness and began to weave a web of intrigues, successfully pitting the two kings against each other.
[24] Hring gathered warriors from Sweden, Västergötland and Norway, while Harald assembled troops from Denmark, the Baltic region and Germany.
The most ferocious champion on Harald's side was Ubbe the Frisian who killed scores of enemies before being shot down by Norwegian archers.
[30] Sigurd Hring, traditionally the father of Ragnar Lodbrok, became the ruler of both Denmark and Sweden but not, it seems, of Norway which was then a patchwork of petty kingdoms.
Paul Herrmann (1922) saw Harald as an "Odin hero" in an (originally) epically cohesive tale, without denying the possibility of a historical kernel.
The archaeologist Birger Nerman (1925), on the other hand, argued that Harald was indeed the overlord over a comprehensive Danish-Swedish realm, while Hring was a sub-king with authority over Sweden, Västergötland and Gotland.
[32] Later, Stig Wikander (1960) hypothesized that the battle was an eschatological myth with parallels to Indian mythology, an idea that has been endorsed by some modern scholars.
[33] The Reallexikon der Germanischen Altertumskunde (1999) suggests that the battle has "perhaps certainly" a legendary and fictitious basis, and that the location to Östergötland is likely a later literary addition.