Björn Ironside (Swedish: Björn Järnsida) (Old Norse: Bjǫrn Járnsíða),[a] according to Norse legends, was a Norse Viking chief and Swedish king. According to the 12th- and 13th-century Scandinavian histories, he was the son of notorious Viking king Ragnar Lodbrok and lived in the 9th century, between 855 and 858.[1] Björn Ironside is said to have been the first ruler of the Swedish Munsö dynasty. In the early 18th century, a barrow on the island of Munsö was claimed by antiquarians to be Björn Järnsidas hög or Björn Ironside's barrow.[2][3] Medieval sources refer to Björn Ironside's sons and grandsons, including Erik Björnsson and Björn at Haugi.[4] Icelandic sagas claim that Björn was the ancestor of the house of Munsö, the line of kings that ruled in Sweden until c. 1060.