Sigurd Snake-in-the-eye () or Sigurd Áslaugsson was a semi-legendary Viking warrior and Danish king active from the mid to late 9th century. According to multiple saga sources and Scandinavian histories from the 12th century and later, he is one of the sons of the legendary Viking Ragnar Lodbrok and Áslaug. His historical prototype might have been the Danish King Sigfred who ruled briefly in the 870s. Norwegian kings' genealogies of the Middle Ages name him as an ancestor of Harald Fairhair and used his mother's supposed ancestry the Völsung to create an ancestry between Harald and his descendants and Odin. Early life "Snake-in-the-eye" as part of Sigurd's name denoted a physical characteristic. He was born with a mark in his eye, described as the image of the ouroboros (a snake biting its own tail). According to Ragnar Lothbrok’s saga, while Sigurd was just a boy, his half-brothers Eric and Agnar were killed by Swedish king Eysteinn Beli (also known as Östen). When Áslaug heard the news of Eric and Agnar's death, even though she wasn't their mother, she cried blood and asked the other sons of Ragnar to avenge their dead brothers. Because the Swedish king controlled Uppsala and a holy cow named Sibilja, Ivar the Boneless believed gods were on Eysteinn's side and feared the magic that ruled there. However, when his younger brother, the three-year-old Sigurd Snake-in-the-Eye, wanted to attack Eysteinn, the brothers changed their minds. Sigurd's foster-father assembled five longships for him. Hvitserk and Björn Ironside mustered 14, and Aslaug and Ivar the Boneless marshaled 10 ships each, and together they took vengeance upon Eysteinn. The Danish historian Saxo Grammaticus relates that Sigurd, as a young man, was close to his father and sojourned for a time in Scotland and the Scottish Islands. After Ragnar's Viking army had slain the local earls, Sigurd and his brother Radbard were appointed sub-rulers of these territories. Later in life Sigurd and his brothers accompanied Ragnar on a hazardous expedition through Rus' to the Hellespont. The death of Ragnar Lothbrok and the Great Heathen Army Most of the legendary sources say that King Ælla of Northumbria killed Ragnar Lothbrok, in about 865, by having him thrown into a pit of snakes. According to traditional accounts, Ragnar is reputed to have exclaimed as he was dying: "How the young pigs would grunt if they knew what the old boar suffers!" Sigurd and