Which son of Ragnar Lodbrok was known as 'Snake-in-the-Eye'?

Sigurd Ragnarsson, better known as Sigurd Snake-in-the-Eye, was the son of Ragnar Lodbrok associated with that distinctive epithet.

The nickname refers to a mark in one of Sigurd’s eyes, described in saga tradition as resembling a snake curled around its own tail, or an ouroboros. Medieval accounts present him as one of Ragnar’s sons by Aslaug, alongside figures such as Ivar the Boneless, Bjorn Ironside, and Hvitserk.

In Ragnarssona þáttr, Sigurd and his brothers avenge the deaths of their half-brothers and later divide territories conquered during their campaigns. Sigurd is said to have ruled Zealand, Scania, Halland, and other Danish lands. The same tradition makes him an ancestor of later Danish and Norwegian rulers through his son Harthacnut.

The stories blend legend, genealogy, and memories of ninth-century Scandinavian rulers, so Sigurd’s exact historical identity is uncertain. He is sometimes connected with the Danish king Sigfred, but the saga character should not be confused with the dragon-slayer Sigurd of the Völsunga saga.