|“||Don't you know who I am? You can't kill me! Don't you know who I am? I am Ivar the Boneless! I am Ivar the Boneless! You can't kill me!||”|
– Ivar challenging the Saxon Army, Homeland
Conceived after his father's return from England, Aslaug had been giving Ragnar several counsels, forewarning things to come. Aslaug had warned that they should not have sex for at least three days, knowing of a prophecy that threatened the prospective child's health, but Ragnar insisted. Because Ragnar did not heed her warnings, Ivar was born with weak bones, his legs twisted and seemingly broken, hence the nickname "Boneless".
When he was born, Aslaug and Ragnar feared for his difficult life. Ragnar, as well as Siggy, suggested that Ivar should be killed, though Aslaug refused. Ragnar once took him out in an attempt to kill him himself; however, Ragnar could not bring himself to do so. When Aslaug told Ragnar his name, Ragnar gave him the epithet "Boneless".
Ivar was tormented with pain, but Ragnar did not care much. Later Harbard seemed to be able to ease Ivar's pain through unknown means. When Harbard left he claimed to have taken some of Ivar's pain into himself and that Ivar would not suffer as much in the future.
Ivar was seen when he was playing with his brothers in Kattegat while being carried in a cart which Ivar tells them not to break his bones. Later he was greeted by Bjorn who just came back from Paris and later in the episode. He said goodbye to Bjorn and he told them to take care of Ragnar. In Yol, Ragnar attempts to involve Ivar in the celebration of Yol and hang a piece of mistletoe as a ornament. Ivar refused and Aslaug took him away from Ragnar. Aslaug stated that Ivar was not like Ragnar and her responsibility, not his. Ragnar said he loved Ivar as much as Aslaug, to which Aslaug replied he did not act like it. Ivar later was brought to Floki by Aslaug to be mentored in the path of a Viking, with Aslaug intending for her son to hate the Christians. Floki seems to bond with Ivar, as they are fellow outcasts.
While Ivar is learning from Floki, he sees various children playing and wants to join them, so Floki puts him in his cart and takes him out among them. Ivar is mostly ignored by the other children despite his pleas for them to toss him the ball, so Floki catches it and tosses it to him. Another child runs up and tries to wrestle it away from Ivar; unable to overcome him in strength, Ivar impulsively picks up a hatchet in his cart and strikes the boy in the head, mortally wounding him. Ivar is horrified; Aslaug hastily comes over to him and tells him it was not his fault.
Years later, in The Last Ship, Ivar defends his father's honour from his brothers, who criticize Ragnar for abandoning them for so many years. Ivar also justifies Ragnar keeping the destruction of their Wessex settlement a secret, stating that the fame from invading Paris (city) was more important. Ivar is later seen greeting Ragnar when he returns.
Ivar is shown to be impotent when his brothers set him up to have sex with a slave girl. The slave girl tells him that potency is not as important as other characteristics. He later has a conversation with Ragnar in which Ragnar asks him to go to England. All other brothers have declined Ragnars invitation to go, Ivar sits in the throne room where Ragnar finds him and Ivar agrees to join his father to travel to England.
As a seer-woman, Aslaug had warned Ivar not to go England, as he would die in a storm. Ivar dismissed this, as he was intent to learn from his esteemed father, and get to know him as a father more than a King. Prior to leaving, with some Saxon gold that Ragnar gave him, he got a town blacksmith to make him a metallic contraption, which enabled him to walk more ably than before. He surprised his parents and brothers with this, and set forth with Ragnar to England.
Ragnar had bribed his former subjects into raiding with him, even those who publicly expressed their hatred of him. They took some ships that Bjorn had lent to them, and pursued across the North Sea to England. Despite an initially calm crossing, they had encountered a heavy storm on the horizon. Once the storm hit, some ships were lost, and they were capsized by a large wave. Aslaug was able to see this, as a seer, and was immensely distraught at her son's apparent death.
However, Ivar and Ragnar, and some of the raiding party, survived. They gathered on a beach, and found a nearby cave to settle in and reformulate a strategy. Ivar's metallic "legs" were also lost in the storm, and his father told him to crawl. However, this was not out of cruelty, as he said this weakness was also his greatest strength.
The party lived off the land for several days, narrowly averting detection by an English girl collecting forest produce for her town or village. Ivar asked Ragnar why he left the kingship, but he did not respond. He did however say that coming to England was his destiny.
Ragnar tells Ivar they must go to the Royal Villa, they kill their fellow Vikings while they are asleep. Ivar and Ragnar arrive at the Royal town and give themselves up. Ivar and Ragnar are seized by Aethelwulf. Ecbert arrives and promises no harm will come to Ivar. Ecbert agrees to hand Ragnar over to King Aelle and arrange safe passage for Ivar to go home.
Ecbert has arranged a ship to take Ivar home. Ragnar speaks with Ivar alone and says goodbye, knowing he will be handed over to Aelle and die. Ragnar tells Ivar to take revenge on Ecbert, and to be ruthless. Ivar returns to Kattegat, to discover that his mother has been killed by Lagertha. Ivar challenges Lagertha to single combat, but is refused, and promises that he will kill Lagertha one day. A man in a black cloak with one eye brings news of Ragnar's death to Ivar. Ivar, Ubbe and Sigurd decide to gather a large army and return to England to avenge Ragnar. An armada of Swedish Vikings, led by Earl Jorgensen, arrives to join the Lothbroks. Ivar and Ubbe attempt to kill Lagertha, but are stopped by Bjorn, who makes clear that his brothers will have to kill him before Lagertha. Floki presents Ivar with a war chariot which will enable him to lead troops in combat. As the great army assembles, Bjorn and Ivar argue over its leadership. The great army lands in Northumbria, King Aelle's much smaller army is overrun, Aelle is captured, and killed by the blood eagle while Ivar is looking into his eye's.
The Vikings arrive at Repton. Before they meet, Ivar persuades Bjorn to scout a potential battlefield and plan to use the terrain to defeat the Saxons. The Vikings then harass the Saxons on the battlefield with archers hidden in the surrounding woods. Prince Aethelwulf decides to move his forces toward the Viking's ships, but the Vikings then ambush them in a tight valley. In panic and frustration, Aethelwulf orders a charge. The Saxons charge into the Norse shieldwall, and suffer heavy losses. Aethelwulf orders a retreat. Ivar demands the blood eagle for Ecbert, but Bjorn reminds his brothers of Ragnar's dream of settlement, and agrees to allow Ecbert to choose his own death in exchange for signing over East Anglia. Ecbert then kills himself in his Roman bath. Bjorn shares his wish to raid the Mediterranean, while Ivar proposes continued raids in England. In an argument over what action to take next, Sigurd starts to insult Ivar and mock his impotence, and Ivar in a fit of rage kills Sigurd by throwing an axe.
A few months afterwards, Sigurd's funeral is held Bjorn and Halfdan leave the Great Heathen Army to sail back to the Mediterranean Sea and king Harald leaves the army as well to sail to Kattegat. Ivar, Hvitserk and Ubbe rule jointly over their newly acquired land in East Anglia. Floki decides to leave the great heathen army to sail to the unknown, Ivar and Floki said there goodbyes. Ivar and Ubbe have an argument to either continue raiding or make peace with the English kingdoms but Ivar persuades his brothers to go north and conquer the city of York and turn it into their stronghold. Ivar, Hvitserk and Ubbe decide to attack the town on Ascension Day, quickly overrunning the meager garrison before butchering the inhabitants, during the battle Ivar shows his brutality by torturing and killing the bishop. Ivar recruits bodyguards and decides to have a tattoo of a giant snake on his back. Ubbe and Hvitsek questioned Ivar as to why does he need a bodyguard and Ivar explains the reason is because he is a cripple. Ivar shows his brothers that he can now stand and walk on his own feet with the help of new leg braces and a crutch.
The Saxons led by King Aethelwulf and Bishop Heahmund entered the town through a section of the old Roman walls that were purposefully neglected by Ivar to lure the Saxons in the town. Once the army formed up, the Saxon forces were split into two. Aethelwulf and Heahmund, Ivar ordered the Danes to fire there arrows, taking out some Saxons. the Saxons were then trapped as the Norsemen raised wooden barricades to contain them while the archers continued depleting their ranks. The Saxons were then lured into small streets and alleyways that were laden with low standing spikes upon which dozens of men fell, fatally wounding themselves. The Danes finally emerged from cover before engaging Aethelwufl's forces into vicious, close-quarter street fighting. Heahmund's force were likewise trapped in a street where the Danes poured oil on the floor before lightning it, which burnt and killed several Saxons. Hundreds of Saxon forces then emerged to confront Ivar, who, in a ferocious stance, provoked the frightened Saxon warriors, claiming they couldn't kill him. While the fight also raged throughout the town, Ubbe's men then came out to meet the Saxons led by Heahmund's.
After the battle the Saxons suffered a crushing defeat. Ubbe and Hvitserk propose a peace, but Ivar wants to continue the war. The two brother secretly leave at night to negotiate with the Saxons, Aethelwulf seemingly accepts their offer, but Heahmund arranges to have the brothers humiliated. With Ubbe having lost face, Ivar secures his position as the leader of the Great Army. Ubbe and Hvitserk prepare to leave for Kattegat with their few followers, however at the last minute, Hvitserk defected to join Ivar. The Saxons laid siege to York, they massacred their hunting parties and blocked the city. the Vikings pretend to burn bodies. Ivar and Hvitserk are in the sewers of the city and Ivar informs Hvitserk that he has a plan. The city is deserted the Saxons celebrate but they are cut short when Vikings appear from the sewers and engage in battle. The vikings win the Saxons retreat. During the battle, Bishop Heahmund is captured and spared by Ivar. Ivar has a conversation with Heahmund about religion and Ivar decides to take the Bishop with him to meet king Harald.
Taking his army, Ivar, Hvitserk and the bishop travled to Vestfold when they arrived they were greeted by Harald. Ivar made and alliance with Harald to attack Kattegat in exchange Ivar promised Harald that he would become his heir and they plan to attack Kattegat in two months' time. Ivar threatens and persuaded Heahmund to fight with them. After two months The army of Ivar, Harald, Hvitserk lin up aginst the forces of Lagertha, Bjorn and Ubbe, meet above Kattegat. Lagertha sends Emissaries then negotiations take place Hvitserk was traded as a hostage for Halfdan. The leaders of the two armies met again the next day. Bjorn Ironsides 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.” Here all diplomacy failed and the armies had to result in battle. Ivar agrees but tricks and mocks Lagertha and her alies. Before battle, Ivar takes Astrid and a third of their army towards shore, to protect their fleet. Hvitserk and his group try to flank, but are ambushed in the forest by the Sami. Battle begins, and Bjorn and Lagertha gain the upper hand, as Harald's forces are outflanked. Ivar hears the fighting, but says it is too late to help. Heahmund is wounded, and Harald retreats.
From birth, Ivar has been subjected to intense pains due to his physical condition, resulting in him receiving very different treatment than the rest of his brothers. Ivar is a monster, he is shown to be easily angered and very arrogant, selfish, cruel, sadistic and psychopathic, as he laughs when he learns of Siggy's death, and does not care about the settlers slain in Wessex, even his own brothers refer Ivar as "Crazy", even killing his own brother Sigard. However Ivar has shown moments where he is remorseful when he breaks down in front of Margrethe saying it is hard being the son of Ragnar Lothbrook and at Sigurd's funeral where he is seen sheding a tear for his brother meaning he had not intended to kill Sigurd. Having been mentored by Floki from a young age, Ivar shares his hatred for Christianity, he also looks up to Floki and gets upset when Floki decides to give his life to the sea. Ivar admires his father for his great fame and successful raids. Ivar deeply loved his mother as she was the only person that showed him a great amount of attention and love, and after her death, he is only close to Ubbe and Floki. Floki practically raised Ivar and he has a fierce devotion to the Norse Pantheon as well.
Ivar also has a keen mind, and immense upper body strength, as account for having to literally crawl in most cases. He shows devotion to his family, and his people, though had a long-running and eventually fatal feud with his elder brother, Sigurd, something has shown no remorse for. During the invasions of England to avenge their father, he impressed his brothers and the other Norsemen with his tactical acumen. Ivar is a tactical genius deciding to attack York because of its strategical importance and tricking the Saxons twice during the battles of Yorktown.
- As of the Season 2 finale, Ivar and his brothers would be known by the Old Norse title of Budlungr or 'prince'.
- Ivar hinn Beinlausi (Ivar the Boneless) is the Old Norse rendering of his name.
- It has been suggested that the historical Ivar suffered from brittle bone disease which rendered his legs useless. In most modern Scandinavian languages the word for "bone" is the same as the word for "leg". The disease also causes Ivar's sclerae (the whites of the eye) to have a blueish hue. However, this is disputed, since there are bones uncovered from Derbyshire in England (where the town of Repton is situated), which are supposedly his own. The skeletal remains show a man of above average height and size, who despite this had a healthy skeletal system.
- Most accounts of Ivar describe him as either incredibly cruel or incredibly wise, or both.
- The King of East Anglia, Edmund the Martyr, was said to have been shot with arrows and beheaded by Ivar, as punishment for refusing to renounce Christianity. This is said to have been near the current English town of Bury St. Edmunds, which was named after him in tribute.
- Ivar is said to have been one of the first Norse kings of Dublin in Ireland.
- Ivar is accounted as being the son who defeated and blood-eagled King Aelle in retribution for his father's death.
- Due to his disease, Ivar suffers from sexual impotence, this is mentioned by Margrethe after they tried to have sex.
- The idea of a lame Viking being tied to a chariot to enter battle comes from the legendary danish king Harald Wartooth, who due his old age, was tied to a chariot at the Battle of Bråvalla in order to face his enemies.
|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 five appearances|
|The Departed Part 1||The Departed Part 2||Homeland||The Plan||The Prisoner|
|The Message||Full Moon||The Joke||A Simple Story||Moments of Vision|