According to Norse mythology, Ragnar was a hero. He was a menace for France and England as he led raids to both countries. Norse mythology says he is a direct descendant of Odin, the god of war. Ragnar is a contested historical figure. According to stories passed down from generations, he seems to be a culmination of several people. Irish lore talks of Reghnal, a warrior who invaded Paris and later died from his injuries. Norse stories talk of Ragnar being a menace to France as well as King of Denmark and Norway. They were probably the same person.
Legend says that Ragnar was married three times. His first wife was the shield maiden Lagertha and then he went on to marry the noblewomen Borgarhjortr. He later marries Auslag. Auslag was the daughter Sigurd and the shieldmaiden Brynhildr. Upon his demise, Ragnar had fourteen children.
Ragnar Lodbrock was a skilled warrior who inspired fear in his enemies. One thing that made him a legend even today, is the fear that his sons would overshadow him. Even after his death, people feared that his sons would cause more damage. So he urged and led raids to his perceived enemies to remind people he was still a vicious warrior.
His most famous raid was in Paris in 845. Ragnar’s forces were so fierce that when King Charles the Bald led the French army to oppose them, the Vikings totally destroyed them. So the French army retreated. Ragnar and his Vikings reached Paris during Easter. Ragnar raided and occupied the city. He would only withdraw from the city after receiving a payment of 7,000 French Livres. He took a liking to attacking France for the most part of the 9th century, and he was successful at it. His exploits and bloodthirstiness created a legend of him. Something striking about him is that he was a witty leader, as mush as he was a ferocious and successful warrior.
Accounts of Ragnar's death strike controversy. Some say his nemesis the Northumbrian king, Aella executed him by dropping him in a pit of snakes. And for that, his sons avenged him. Others say he died from his injuries from raiding Paris. Legend has it that on hearing the news of how their father died, two of his sons, swore to avenge him. Legend even says that when the sad news of Ragnar’s death arrived one of his sons, Halfdan was playing chess. The news was so difficult for him that he gripped a chess piece so hard that his nails bled. In 866, in an attempt to avenge their father, several of Ragnar's sons crossed the North Sea with a massive fleet. It became known as the Great Heathen Army.
This lasted for 14 years. Unlike many of the Scandinavian raiding armies of the period, surviving sources give no firm indication of its size, but it was most definitely amongst the largest forces of its kind.
Ragnar's sons attack England but Ivar the Boneless, one of Ragnar's most famous sons, does not want to fight as the English army is very large, he fears they will lose and he will have to go home again. Ivar still stays in England and asks Aella for wergild. He claimed he can not go home without some compensation to show his brothers. Ivar asked for as much land as he can cover with an ox's hide. It was cut into such a fine long string of hide that he can encircle an area large enough for a city. When this is done, he lays the foundations for a city which became York. He allied himself with all of England and finally all the chieftains in the region become loyal to Ivar and his brothers.
Ivar tells his brothers to attack England. During the battle Ivar sides with his brothers and so do many of the English chieftains with their people, out of loyalty to Ivar. Aella is captured and in revenge, Ragnar's sons carve the blood eagle from him. To carve the blood eagle from someone, means to have the victim lying on their stomach, the back is slit along the spine, and the ribs are bent so they expand like wings.
Ivar becomes king over north-eastern England which his forefathers owned and and he has two sons. Ivar's sons obey their father and tortured King Edmund the Martyr and took his realm. Lagertha, his first wife was equally badass but she deserves her own mytake.