Sigurd Snake-in-the Eye: Son of Ragnar, Raider, and Ruler
Sigurd "Snake-in-the-Eye" Ragnarsson is not as famous as other brothers. However, nobody can doubt his fighting skills and strategic mind. While little sources mentioned offsprings of other brothers, the descendants of Sigurd included Harthacanute I, Gorm the Old, Harald Bluetooth.
Sigurd Snake-in-the-Eye was one of four legendary sons of King Ragnar Lothbrok, a great Viking King. His mother's identity was quite obscure yet nearly all materials said it was Kraka that mothered Sigurd. Kraka was a seeress and she was the daughter of Valkyrie Brynhildr.
As the name indicated, Sigurd had a mark in his eye. When he was born, his mother prophesied about this mark. It was a symbol of an Ouroboros - a snake biting its tail like Jormungand the Serpent encircling Midgard.
The Ouroboros mark in the eye of Sigurd (Cre: "Vikings" TV Series)
When he was a boy, he had a very good relationship with his father, King Ragnar. On expeditions, Ragnar often brought Sigurd with him.
In 865, King Aella of Northumbria executed in a pit full of serpents. The scholars believed that King Aella was trying to dishonour Ragnar Lothbrok because Ragnar was believed to kill an enormous serpent. Ragnar's last words have always become excitingly famous: "How the little piggies will grunt when they hear how the Old Boar suffered?"
And shortly after, revenge for revenge. King Aella made a terribly wrong move to send a message to inform Ragnar's sons of Ragnar's death. Hearing the news of father's death, Sigurd cut himself to the bone with and Bjorn Ironside gripped his spear so tightly that he nearly broke it.
The values of Ragnar's family or generally the Vikings upheld meant they would never spare a life for their enemy. Assembling a great military army, they formed Viking Great Heathen Army (the name that got mentioned in the Anglo-Saxon Chronicle). They sacked York meeting King Aella in battle and executed the King with Blood Eagle.
Later life and legacy
Coming back to Denmark, Ragnar's sons shared the father's lands with Sigurd taking Zealand, Halland, Oslo, Fjord, and Skane. What's still a matter of debate for the historians is that Sigurd married Heluna King Aella's daughter.
Ragnar's sons declared eternal war on the killer of their father Ragnar Lothbrok
Ragnar's sons continued to raid around other parts of Europe as a nightmare befalling their enemies. They were also noted to be the first Viking warriors to bring the raven banner into battle. If the raven flapped its wings, they were to win the battle. But if the raven became motionless, the brothers would be welcomed to Valhalla with Odin the Allfather.
Sigurd Snake-in-the-Eye was allegedly fell with his brothers in the battle of Leuven in 891. Hearing the death of her son, Kraka emotionally exclaimed:
"Sad sit the corpse-stalkers,
slaverers after cadavers:
The slain-craver, raven
What a shame! - forsaken
By namesake of Sigurd;
In vain now they're waiting.
Too soon from life Lord Odin
Let such a hero go."
Harthcanute Sigurdsson succeeded his father as the King of Zealand, Scania, and Halland. Later, Harthcanute fathered Gorm the Old King of Denmark which made him become the grandfather of Harald Bluetooth Gormsson who united the Danes under a banner.