Ivar the Boneless also known as Ivar Ragnarsson, was a Viking leader who invaded Anglo-Saxon England. According to Tale of Ragnar Lodbrok, he was the oldest son of Ragnar Loðbrok and third wife Aslaug. His younger half-brothers and brothers included Björn Ironside, Halfdan Ragnarsson, Hvitserk, Sigurd Snake-in-the-Eye and Ubba. The origin of the nickname is not certain. "Ívarr beinlausi" could be translated to "Ivar legless", but "beinlausi" could also be translated as "boneless", since "bone" and "leg" translates to the same word, "ben", in Swedish. Several of the sagas describe him as lacking legs/bones, while a passage in Ragnarssona þáttr (also known as the tale of Ragnar's sons) suggest it refers to male impotence with Ivar's "Bonelessness" being merely figurative. According to the Tale of Ragnar Lodbrok, Ivar's bonelessness was the result of a curse. His mother Aslaug was Ragnar's third wife. She was a völva. She said that she and her husband must wait three nights before consummating their marriage after his return following a long separation (while he was in England raiding). However, Ragnar was overcome with lust after such a long separation and did not heed her words. As a result, Ivar was born with weak bones. Another hypothesis is that he was actually known as "the Hated", which in Latin would be Exosus. A medieval scribe with a basic knowledge of Latin could easily have interpreted it as ex (without) os (bone), thus "the Boneless", although it is hard to align this theory with the direct translation of his name given in Norse sources. While the sagas describe Ivar's physical disability, they also emphasise his wisdom, cunning, and mastery of strategy and tactics in battle. He is often considered identical to Ímar, the founder of the Uí Ímair dynasty, which at various times, from the mid-ninth to the 10th century, ruled Northumbria from the city of York, and dominated the Irish Sea region as the Kingdom of Dublin.