Ivar the Boneless ( ; 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 Ragnar Loðbrok and his wife Aslaug, as his brothers Björn Ironside, Hvitserk, Sigurd Snake-in-the-Eye and Ubba, however, this is not sure to be historically accurate. Ivar is probably the same person as Ímar, a Viking king of Dublin between 870-873. 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, "bein", in Old Norse. Several of the sagas describe him as lacking legs/bones or having a skeletal condition such as osteogenesis imperfecta, while a passage in Ragnarssona þáttr (also known as the tale of Ragnar's sons) suggest it refers to male impotence. Sources According to the Tale of Ragnar Lodbrok, Ivar's bonelessness was the result of a curse. His mother, Aslaug, Ragnar's third wife was described as a völva, a seer or clairvoyant. Aslaug suggested that she and her husband wait for three nights before consummating their marriage after a long separation while he was in England raiding. However, Ragnar was passionate 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 only 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 tenth century, ruled Northumbria from the city of York, and dominated the Irish Sea region as the Kingdom of Dublin. This would also make him the ancestor of the Crovan Dynasty. Chronology 865 the Great Heathen Army, led by Ivar, invaded the Anglo-Saxon Heptarchy. The Heptarchy was the collective name for the seven kingdoms East Anglia, Essex, Kent, Mercia, Northumbria, Sussex and Wessex. The invasion was organised by