Sigvard was domineering and abusive, often asserting his power and ownership over Lagertha. He was brutal, ill-tempered, beating Lagertha when she talked back to him. Sigvard and Bjorn came at odds, and Sigvard took pleasure in insulting and humiliating him in front of his people. Sigvard claimed that Bjorn started the conflict by not accepting him as his father and his love for him. Lagertha asserted that Sigvard had no love for anyone but himself. He generally disliked talking about Ragnar, possibly due to a inferiority complex.
At a dinner, Sigvard questioned why Bjorn is so sullen (Bjorn had just found out Sigvard was beating his mother) and mockingly suggests if they should raid a neighboring earldom so Bjorn can prove his strength. Bjorn asks for Sigvard's permission to go out in the woods, to learn the essentials of life. Sigvard replies that he will not risk his reputation by allowing his stepson to possibly starve in the wilderness.
When Lagertha returns to Earl Sigvard after helping her previous husband Ragnar drive Jarl Borg out of Kattegat, he openly berates her for her absence without his permission. Moreover, he is unhappy that his stepson, Bjorn, stayed with his father in Kattegat. After accusing her of still being in love with Ragnar, he tells her to sleep alone that night, that he's made "other arrangements." Later, he sends some of his men to beat her up and possibly rape her.
At a feast in his hall, he drunkenly claims that the bruised and battered Lagertha has the most beautiful breasts of any woman in the world and that they are like Freyja's breasts. To further demean and humiliate her, Sigvard rips her dress open to show his people Lagertha's breasts, but having had enough, she grabs a knife and stabs out one of his eyes. Screaming in pain, Sigvard falls to his knees. With the hall in shock and before anyone knows what to do, his nephew, Einar, draws his sword and approaches, seemingly to kill Lagertha. He instead beheads Sigvard, sending the earl's head rolling on the rough, wooden floor. Sigvard's people where shown at several earlier point to be uncomfortable with their earl's behavior and Einar's family supported the killing of him: few protested the murder.
- As the apparent Earl of Hedeby, Sigvard ruled over one of the more important commercial centres in all of Scandinavia. Hedeby (also known as Haithabu in German) lies a short distance from the Treene River, which flows into the North Sea. The Treene itself is a tributary of the Eider River, which itself flows closely toward the Baltic shoreline. Hedeby was also very close to the Danevirke, the line of defensive earthworks, strengthened under the directive of King Gudfred (father of Horik), which served to define the boundary between Denmark and Saxony, which then under the rule of the Christian Franks who posed a danger to the Danes.
- Hedeby was in Jutland and so Earl Sigvard and his people would have been Jutes, who had become merged with the rising Danish kingdom prior to the Viking Age. The Jutes were among the North Germanic tribes who previously took part in the migrations to Britain.
|Season two appearances|
|Brother's War||Invasion||Treachery||Eye For an Eye||Answers in Blood|
|Unforgiven||Blood Eagle||Boneless||The Choice||The Lord's Prayer|