Hvitserk was born in the four year gap between Season 2 Episodes 1 and 2. Hvitserk is often seen alongside his brother Ubbe, and likely looks up to him. Ubbe flees with Aslaug, Ubbe, Rollo, Siggy, and Helga after Jarl Borg invades Kattegat. Ragnar eventually returns from England where he is reunited with his family, and with the assistance of Lagertha, he takes back Kattegat.
An older Hvitserk is seen playing with his brothers Ubbe and Sigurd. One day while Aslaug is away and Siggy is watching them Ubbe and Hvitserk wander off onto a frozen lake and Siggy pursues them. She calls out to them, but despite them knowing she is there, Ubbe and Hvitserk ignore her. The ice breaks and Ubbe and Hvitserk fall in. They both nearly drown but Siggy dives in and saves them with the help of Harbard but at the cost of Siggy's life as she drowns.
Ubbe and Hvitserk receive their arm-rings from their father so that they can come to Paris with him but not to fight. The Franks then attack the Viking camp but Ubbe and the others manage to escape, but Helga is wounded. After the Vikings' defeat at the hands of Rollo and the Franks they return to Kattegat with the broken and defeated Viking Army.
Ten years later, with Ragnar having disappeared, Hvitserk has grown up into a strong and skilled warrior like all of Ragnar's sons. Having grown up without his father present, Hvitserk has grown resentful and angry at Ragnar. Bjorn brings the news that the Danish settlement in Wessex was destroyed. Hvitserk and his brother discuss why Ragnar didn't tell anyone. Hvitserk then says that if their father ever returned he would kill him, which Sigurd agrees with. Ivar gets angry at his brothers for insulting their father and refers them as "Christians" and calling them soft. Ragnar then returns to Kattegat after his long absence a broken man. He reunites with his sons and challenges his sons to kill him, especially Ubbe, so that they can become king. Ragnar tries to provoke Hvitserk into kill him by screaming at him to kill him, but Hvitserk doesn't move. Eventually Ubbe steps forward, but he and Ragnar only embrace. Ragnar and his sons discuss the lost Wessex settlement and why he came back. Ragnar asks his sons to come to England with him. Hvitserk refuses saying he is sailing with Bjorn to the Mediterranean with Harald, Halfdan, and Floki.
Once Floki's ships are ready, Hvitserk and the group travel to Frankia where they try to bargain with Rollo, who is now the Duke of Normandy, to let them past his coastline so they can travel to the Mediterranean without any trouble. Hvitserk is introduced to his cousins William, Marcellus, and Celsa. However they are imprisoned, but Rollo agrees to let them go as long as he accompanies them. They reluctantly let Rollo come, but not before knee hauling him for his betrayal all those years ago.
Hvitserk, Bjorn, Harald, Halfdan, Floki, and Rollo then sail down the Mediterranean and arrive in Spain, where they slaughter any resistance and steal any treasure they can get there hands on. While staring out to the ocean on a cliff, Odin himself approaches Hvitserk and Bjorn and tells them their father is dead. Hvitserk and Bjorn return to Kattegat, dropping Rollo back in Frankia on the way. Hvitserk returns home and finds out that Ubbe has freed Margrethe, their lover and is marrying her. Hvitserk is delighted and asks Ubbe to "make sure he doesn't keep her all to himself." After the marriage ceremony Ubbe says that he and Hvitserk can share Margrethe since they both love her. Hvitserk, Ubbe, and Sigurd then discuss their mother's death. Hvitserk says they shouldn't kill Lagertha because she was a bad mother. Ivar says they should, and Hvitserk replies that Ivar is crazy.
Hvitserk and his brothers summon and form the Great Heathen Army to avenge their father. They easily defeat the forces of Northumbria and kill King Aelle with a blood eagle ceremony. The Great Heathen Army then faces the forces of Wessex, confusing and outmaneuvering them, causing them to retreat. They capture King Ecbert and Bishop Edmund. Ivar demands a blood eagle for King Ecbert but Ubbe and his brothers convince Ivar otherwise. Later, Hvitserk watches in horror as Ivar kills Sigurd by throwing an axe into his stomach. Hitserk and Ubbe look at Ivar in anger for killing his own brother, while Ivar shows no remorse.
After Sigurd's death, Hvitserk, Ubbe, and Ivar rule jointly over their newly acquired land in East Anglia. Floki decides to leave the Great Heathen Army to set sail for the unknown, Hvitserk and the army say their goodbyes to Floki. Ivar persuades Hvitserk and Ubbe to go forth and conquer the city of York. Hvitserk and the Great Heathen Army attack York when the locals are celebrating one of their saints. The attack is a success. They easily sack and occupy the city. After the successful attack and occupation of the city, Hvitserk and Ubbe go to speak with Ivar. They are surprised to see that he now has bodyguards, who initially try to stop them. Ubbe just stares them down until they step aside. They find Ivar getting a large tattoo on to his back, and ask him why he needs bodyguards. "Because I'm a cripple!" he states. They ask him why did he not consult them about it and if he thinks he is the leader of the Great Heathen Army. He answers, "Why would I think such a thing?" He then shows his brothers the newly created leg braces and crutches that were specially made in order for him to walk on his own.
The Saxons, led by King Aethelwulf and Bishop Heahmund, enter the town through a section of the old Roman walls that were purposefully neglected by Ivar to lure the Saxons in. After the battle, the Saxons suffered a crushing defeat. Hvitserk and Ubbe propose peace, but Ivar wants to continue the war. The two brothers secretly leave at night to negotiate with the Saxons. Aethelwulf seemingly accepts their offer, but Heahmund arranges to have the brothers humiliated. With Ubbe and Hvitserk having lost face, Ivar secures his position as the only leader of the Great Heathen Army.
Hvitserk and Ubbe prepare to leave for Kattegat with their few followers. But at the last minute, Hvitserk defects to join Ivar. The Saxons lay siege to York, they massacre the hunting parties and block the city. The Vikings pretend to burn bodies, and Ivar humiliates Hvitserk by not sharing his plan. Hvitserk and Ivar are in the sewers of the city when Ivar finally informs Hvitserk that he has a plan. The Saxons arrive in York thinking the city is deserted. Their celebration is cut short when the Vikings appear from the sewers and engage in battle. Bishop Heahmund is taken captive. Hvitserk and Ivar decide to take him with them to Kattegat.
The Great Heathen Army travels to Vestfold where they are greeted by King Harald. Ivar makes an alliance with Harald that if he helped them attack Kattegat, Ivar would name Harald as his heir. They plan to attack Kattegat in two months' time. Hvitserk questions Ivar about why would he make Harald his heir and Ivar states, "Who's to say he will not die." Ivar threatens and persuades Bishop Heahmund into fighting with them. After two months, their army lines up against the forces of Lagertha, Bjorn, and Ubbe above Kattegat. Lagertha sends emissaries to begin negotiations. Hvitserk is traded as a hostage with Halfdan. Ubbe pleads unsuccessfully for Hvitserk to side with them. The leaders of the two armies met again the next day. Bjorn begs Ivar to consider the possibility of peace, stating that a civil war can only bring tragedy and “a lifetime of revenge obligations for those who survive.” Ivar agrees but tricks and mocks Lagertha and her allies. This results in failure for a peaceful end to the conflict. Before battle, Ivar takes Astrid and a third of their army towards shore to protect their fleet. Hvitserk and his group try to flank Bjorn and Lagertha's army, but are ambushed in the forest by the Sami. Battle begins, and Bjorn and Lagertha's side gains the upper hand, as Harald's forces are outflanked. Ivar hears the fighting, but says it is too late to help. Bishop Heahmund is wounded, and Harald retreats. During the battle, Hvitserk kills Torvi's son Guthrum. He seems to be gleeful about killing him.
Later, Hvitserk falls in love with Thora. When Hvitserk is gone to meet with King Olaf on Ivar's orders, Ivar has her and her family killed, along with all those who oppose his rule. Upon discovering what happened to Thora, Hvitserk rejoins his other brothers to defeat Ivar during the Siege of Kattegat. Ivar loses Kattegat, but escapes with his life.
Much time has passed, and Hvitserk has been spiraling downward through a combination of unraveling mental health and addiction to alcohol and mushrooms. Despite this, Bjorn decides to let Hvitserk take care of Kattegat while he goes to rescue King Harald from King Olaf. Ubbe tells him that Hvitserk is not in any condition to be in charge. Amma, who deeply cares about Hvitserk, becomes his caretaker. Trying to give his brother something productive to do with his life, Ubbe assigns Hvitserk a trade mission along the old Silk Road to lead. When Hvitserk fails to sober up, Ubbe becomes angry and feels betrayed. He yells at Hvitserk that he never wants to see him again.
Later while hallucinating, Hvitserk follows an imaginary serpent he thinks is Ivar. He catches it and begins stabbing it to death. Too late, he realizes it wasn't Ivar he killed, but Lagertha who was limping back to Kattegat after defeating White Hair’s second raid. He confesses to Bjorn about Lagertha's murder and Bjorn thrashes him and arrests him. Hvitserk says that he hasn't achieved anything great like Bjorn or Ubbe, telling Bjorn, "Even if you wants to burn me alive, I'll accept it, because I have deserved it." At first deciding to burn Hvitserk alive, Bjorn changes his mind and allows Ubbe to save him. Instead of killing him, Hvitserk is exiled as an outlaw, or a Skogarmaor.
Hvitserk is later reunited with Ivar who has come to invade Scandinavia with Prince Oleg. Hvitserk decides that staying with Ivar is a better choice because Ivar has matured. He feels that Ivar treats him better than Bjorn and Ubbe.
Hvitserk is the quiet one of the brothers. After Ivar, he is the most violent, bloodthirsty, and quickest to jump into battle. He is very impulsive and doesn’t tend to consider the consequences of his actions. For example, he leaves his lover Thora with Ivar even though Ivar has repeatedly made giddy suggestions that he sacrifice Hvitserk or Thora to himself. Then when Hvitserk hears the obvious outcome of Thora’s death took place, he acts with genuine shock. Despite being a definite follower rather than a leader like his brothers are, he feels he deserves just as much honor and glory as they do. Hvitserk dislikes both of his parents. Feeling abandoned by Ragnar, he flat-out says he’d kill Ragnar if he came back during his ten-year disappearance. While to a lesser degree than Sigurd, he dislikes Aslaug. He says that he couldn’t care less when Lagertha kills her. However, in Season 6 he admits that walking around the place where she was killed makes him remember it, suggesting he has similar visions of her dying like has with Thora. Though he would be loath to admit it, Hvitserk is the son who resembles Aslaug the most, both physically and mentally. Like her, he demands respect he hasn’t earned, has a definite sense of entitlement purely born from being the son of a famous person, isn’t that good at reading a room or the people in it, and tends to whine about his problems rather than take steps to solve them.
As a warrior, Hvitserk is leans toward being a Berserker, going wild during battles. During the Sack of York, he goes on a killing spree, hacking down people until he collapses out of sheer exhaustion on the floor covered in blood. Like Ivar, Hvitserk is vicious and enjoys killing far more than Ubbe, Sigurd, or Bjorn. If Ivar treated him better, they might have gotten along. While most of his brothers tend to not engage in rape during raids, Hvitserk is the one who engages in raping women the most. It happens both when he’s with Bjorn in Algeciras, Spain and in York, though all implied off-screen.
Perhaps his best-known trait is his inability to stay on the side of one brother for too long. He’s closest to Ubbe for a long time, but literally jumps ship to be with Ivar, his axe crazy brother, instead of Ubbe, his overbearing brother. Then when Ivar’s constant mockery and murder of Margarethe become too much, he betrays Ivar by attacking Kattegat with King Olaf, Harald, Lagertha, Ubbe, and Bjorn. Hvitserk believes he sided with Ivar because their fates are linked. After exploring Buddhism, he begins to question this, but ultimately comes to believe that his fate is to kill Ivar. But then he decides that Ivar might be the right person to stay with as Ivar has matured a bit between Season 5B and Season 6A.
Throughout Season 6, Hvitserk has become a man who feels lost and is constantly searching for something to live for or someone to follow. He has been going on a downward spiral of drinking and taking mushrooms. He has lost both of his parents and the two women he’s loved, the latter two because of his brother Ivar. Most of his remaining family has left him to his own devices as he is tormented by visions of Ivar as a serpent and of a burned Thora demanding revenge. Hvitserk lashes out and ends up beating Amma, the only person left that worries about him. He runs out into the rain hunting after an imaginary serpent Ivar. He finally attacks it, in the very place where Aslaug died no less, and stabs it for all it’s worth. When he returns to his senses, he sees that he actually stabbed Lagertha who was limping back to Kattegat after defeating White Hair’s second raid. The Seer had given Hvitserk a prophecy, which turned out to be his last one. He says that Hvitserk “will do what his brothers have failed to do, but the cost will be too high.” When he murders Lagertha, he fulfills the Seer’s prophecy.
- As of the Season 2 finale, Hvitserk and his brothers would be known by the Old Norse title of Budlungr or "prince."
- It is often suggested that Hvitserk is the same individual as Halfdan, another name said to be the son of Ragnar. The Norse sagas name him Hvitserk, while Anglo-Saxon sources refer to a brother named Halfdan, and for this reason historians generally assume they are the same person.
- If Hvitserk is the same person as Halfdan, then he was one of the principle leaders of the Danish Mycel Heathen Here (the Great Heathen Army) and assisted with the conquests of Northumbria, East Anglia, and the northern half of Mercia. Briefly, between 871-872, Halfdan/Hvitserk would occupy the city of London, then part of the kingdom of Mercia.
- According to history, Hvitserk/Halfdan died in battle at the hands of fellow Vikings in Northern Ireland. He was king in Dublin but his rule was not secure there and while he was away in York, where he also was king, they deposed him. He sailed back to Ireland with an army in 877 to recapture Dublin. But he was met with an army of what the sources call “Fair Heathens” and Hvitserk/Halfdan himself led an army of “Dark Heathens.” Both were rivaling groups of Vikings in Britain and Ireland. There was a battle at a place called Strangford Lough in which Halfdan/Hvitserk was slain and his army also defeated.
- The saga The Tale of Ragnar's Sons, which calls him Hvitserk, mentions that he led armies into Gardariki (the Norse term for Russia), where he lost a battle facing overwhelming odds. It claims that he was burnt alive by his captors.
- According to the saga Tale of Ragnar's Sons, Hvitserk inherited Jutland (Danish mainland) and Wendland (Luchow-Dannenberg in Lower Saxony) after the death of his father.
|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|
|Season three appearances|
|Mercenary||The Wanderer||Warrior's Fate||Scarred||The Usurper|
|Born Again||Paris||To the Gates!||Breaking Point||The Dead|
|Season four appearances|
|A Good Treason||Kill the Queen||Mercy||Yol||Promised|
|What Might Have Been||The Profit and the Loss||Portage||Death All 'Round||The Last Ship|
|The Outsider||The Vision||Two Journeys||In the Uncertain Hour Before the Morning||All His Angels|
|Crossings||The Great Army||Revenge||On the Eve||The Reckoning|
|Season six appearances|
|New Beginnings||The Prophet||Ghosts, Gods, and Running Dogs||All The Prisoners||The Key|
|Death and the Serpent||The Ice Maiden||Valhalla Can Wait||Resurrection||The Best Laid Plans|
|King of Kings||All Change||The Signal||Lost Souls||All At Sea|
|The Final Straw||The Raft of the Medusa||It's Only Magic||The Lord Giveth||The Last Act|