is a mythical Viking we only know from the sagas and there are various spellings of his name: Ragnar or Regnar. The same goes for his nickname: Lodbrog, Lodbrok, Lodbrock.
However the oldest is Loðbrókawhich comes closest to the original name.
He is most likely a composite character of several historical persons.
Some have therefore argued that he never existed. However several of his sons are known historical figures and are also mentioned in Christian annals. This is the one man who lived on in legends far more than any of the others!
The aim of this project is to tell the Story of Ragnar and that of his children as we have become to know them from the sagas
'Sagas are not facts but still undeniably connected to real historical events.
Ragnar "Lodbrok" Sigurdsson, Konge af Danmark og Norge
There are two of the most famous tales of Ragnar which is the saga of Ragnar and the saga of Ragnar’s sons.
Saxo Grammaticus mentions both him and sons in detail.
Heimskringla is a Norwegian page, that has the different sagas, mostly in the native tung.