Ivar the Boneless (Old Norse: Ívarr hinn Beinlausi [ˈiːˌwɑrː ˈhinː ˈbɛinˌlɔuse]; died c. 873), also known as Ivar Ragnarsson, was a Viking leader who invaded England and Ireland. According to the Tale of Ragnar Lodbrok, he was the son of Aslaug and her husband Ragnar Loðbrok, and was the brother of Björn Ironside, Halvdan (or Hvitserk), Sigurd Snake-in-the-Eye, and Ragnvald. However, it is not known whether or not this is historically accurate. Ivar is sometimes regarded as the same person as Ímar, a Viking king of Dublin between 870 and 873.[2] He might have been born in Uppsala, Sweden in about 787.[3]
It is unclear why Ivar acquired the nickname "boneless". Some sagas claim that he was born with a skeletal condition which left him unable to walk, while others suggest that he was merely impotent.[4]