Ivar the Boneless was a Viking chieftain who was said to be the son of the Danish king
In Vikings, Ivar is portrayed as the son of Ragnar and Aslaug and a younger half-brother to Björn Ironside. He first appeared in season 2 as a baby, and later was played by James Quinn Markey and Alex Høgh Andersen.
Legends tell us that Ragnar – son of King Sigurd Hring – had three wives, the third of whom was Aslaug, who bore him sons Ivar the Boneless, Bjorn Ironside and Sigurd Snake-in-the-Eye, all three of whom would grow greater in stature and fame than he.
Historically: According to the old Norse story “The Tale of Ragnar's Sons,” Ivar was the firstborn of Ragnar and Aslaug, followed by Bjorn, then Hvitserk, then Sigurd. Other Norse sagas list a different set of brothers, including Ubbe and Halfdan.
Ragnar is said to have been the father of three sons—Halfdan, Inwaer (Ivar the Boneless), and Hubba (Ubbe)—who, according to the Anglo-Saxon Chronicle and other medieval sources, led a Viking invasion of East Anglia in 865.
Vikings: The Sons of Ragnar, Ranked By Fighting Ability - IMDb. In Vikings, the Sons of Ragnar go on to surpass even their own father's legacy. Bjorn, Ubbe, Ivar, Hvitzerk, and Sigurd are some of the most powerful characters in the series, and each seems to be connected to a particular part of Ragnar's personality.
Ragnar Lothbrok had at least seven sons. According to the historical accounts of Ragnar Lothbrok, through his first marriage, he had two sons, Agnar and Eric. Through his second marriage, he may have had five sons. Ivar the Boneless, Sigurd Snake-in-the-eye, Bjorn Ironside, Ubba, and Hvitserk.
As the oldest son of Ragnar and the only surviving child of Ragnar and the famous shield-maiden Lagertha, Bjorn already has the makings of a great warrior. Both of his parents are well-known for their actions during battle, and their leadership outside it.
Magnus, now a man, returns to Wessex and falsely claims to be a son of Ragnar to Björn and proclaimes he wanted revenge on the new King Alfred, blaming him and the late Ecbert and Aethelwulf for his exile and causing the death of "their father" Ragnar.
According to medieval sources, Ragnar Lothbrok was a 9th-century Danish Viking king and warrior known for his exploits, for his death in a snake pit at the hands of Aella of Northumbria, and for being the father of Halfdan, Ivar the Boneless, and Hubba, who led an invasion of East Anglia in 865.
Ivar the Boneless died of an unknown disease in 873. Ubba was killed in action probably around 878 in a battle with the Saxons. Sigurd Snake-in-the-eye's death is unknown. It is only known that he was overthrown by Olaf the Brash around the year 900.
The death of Baldur is ultimately the result of Ivar the Boneless' failure to heed his father's advice. During their two-man "raid" of Wessex, Ragnar told Ivar the Boneless that his deformity had made him the strongest out of all his brothers and that it was a blessing rather than a curse.
It states that Björn was the son of Ragnar and Aslaug and that his brothers were Hvitserk, Ivar the Boneless, and Sigurd Snake-in-the-Eye. The tale also tells of Björn's half-brothers Eric and Agnar. The saga portrays Ragnar as the overlord of large parts of Sweden and possibly even Denmark.
Ivar made a surprising decision in the Vikings series finale, sacrificing himself in order to save the life of his brother Hvitserk. He is then killed by a Wessex soldier during the show's last epic battle.
The character of Ivar the Boneless (kind of) had a son in Vikings season 5, but the baby Baldur was left in the forest to die due to a facial deformity — so, what was wrong with Ivar's son?
Bjorn Ironside
Yes, Ragnar and Lagertha's son/their only surviving child dies in Episode 11 (“King of Kings”) of Season 6 (full recap here). A dying Bjorn leads the charge for Norway to defeat the Rus after several life-ending arrows get shot at him by a Rus soldier.
Some suggest that Ragnar was lying in order to save the prince so the Saxons wouldn't use him against him, which led to Aethelwulf freeing the boy. Magnus returned in Vikings season 5 and claimed to be Ragnar's son to Björn and wanted revenge for his exile and Ragnar's death.
Ragnar supposedly had an illegitimate son, Magnus, who returned after Ragnar's death to avenge his death and other issues he had with some English royals. Magnus of Mercia was the son of Queen Kwenthrith, who claimed that Magnus' father was Ragnar Lothbrok.
Sigurd. Sigurd Snake-in-the-eye was one of the smarter sons of Ragnar Lothbrok when it comes to emotional and social intelligence.
After having avenged his father together with his brothers, he went to Gardarike (Garðaríki). Hvitserk also pillaged with the Rus. He was, however, opposed by such a large foe that he could not win. When asked about how he wished to die, he decided to be burned alive at a stake of human remains.
It's unknown which year Vikings season 4 is set in, and as Ragnar didn't seem to age much throughout the series, fans get confused over his age. The “real” Ragnar might have died sometime between 852 and 856, which in the series would have made him 89-93 years old, which doesn't seem possible.
Battle of Arx Cynuit. Wind Hill, near Countisbury, Devon, possibly the site of the Viking defeat at the hands of local men in 878. Some mediaeval sources claim that Ubba led the vanquished army, and that he was among those slain.
Björn dies in Vikings season 6 after being stabbed by Ivar with a sword. Though, he didn't die on the spot and managed to pull one final trick on his enemies. However, Björn's wounds were so severe he eventually passed away, but his legacy continued until the final episode of Vikings.
Bjorn's classic moniker was derived from the belief that he was rarely wounded in battle, in fact, it was thought that he was invulnerable to any wound. The largest mound on the island of Munsö located in lake Mälaren is said to be the final resting place of this legendary Viking.
When Lagertha died, she was shown entering Valhalla, escorted by the Valkyries, and lying next to Ragnar, confirming that he went to Valhalla despite being baptized and not dying in battle.