Styrbjörn the Strong (Old Norse: Styrbjǫrn Sterki [ˈstyrˌbjɔrn ˈsterke]; died c. 985) according to late Norse sagas was a son of the Swedish king Olof Björnsson, and a nephew of Olof's co-ruler and successor Eric the Victorious, who defeated and killed Styrbjörn at the Battle of Fyrisvellir.
According to legend, his original name was Björn, and Styr-, which was added when he had grown up, was an epithet meaning that he was restless, controversially forceful and violent.
In modern days, he is also the hero of a novel called Styrbiorn the Strong by English author E. R. Eddison (1926),[4] and he is featured in The Long Ships, by Frans G Bengtsson.
Nús Danmarkar dróttinn í drengja lið genginn; landa vanr ok lýða lifir ánauðigr auðar.
The contemporary skald Þórvaldr Hjaltason also described the Battle of Fyrisvellir in the following pair of lausavísur, for which Eric rewarded him with two rings both worht a half mark, one for each stanza: Fari* til Fýrisvallar, folka tungls, hverrs hungrar, vǫrðr, at virkis garði vestr kveldriðu hesta.
Þar hefr hreggdrauga hǫggvit — hóll*aust es þat — sólar elfar skíðs fyr ulfa Eirekr í dyn geira.
Illr varð ǫlna fjalla auðkveðjǫndum beðjar til Svíþjóðar síðan sveimr víkinga heiman.
Þat eitt lifir þeira, — þeir hǫfðu lið fleira — — gótt vas her at henda Hundings — es rann undan.
His uncle Eric did not want him to stay at home, because of his violent nature and the complaints from the free farmers, so he gave Björn 60 well equipped longships, whereupon the frustrated boy took his sister Gyrid and left.
When they arrived at Föret (Old Norse Fyris) in Uppland, he burnt the ships in order to force his men to fight to the end.
Harald then conquered the land of the Slavs and took the stronghold Julin (Jomsborg), which he gave to Styrbjörn to command with a strong force.
In the 18th century, Danish historian Jacob Langebek proposed that Styrbjörn and Tyra were the parents of Thorkel Sprakalegg, who was father of Ulf the Earl and of Gytha Thorkelsdóttir, wife of Godwin, Earl of Wessex, and thus grandfather of kings Sweyn II of Denmark and Harold Godwinson of England.
[11][12] The earliest known source which says anything about the father of Thorkell Sprakalegg was the chronicle of John of Worcester, who says that 'Spraclingus' was son of 'Urso', (Latin for bear) which would be Bjorn.