Björn Ironside (Old Norse and Icelandic: Björn Járnsíða, Swedish: Björn Järnsida) was a semi-legendary king of Sweden who would have lived sometime in the 9th century. Björn Ironside is said to have been the first ruler of a new 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 grave. Hög, from the Old Norse word haugr, means barrow or mound.
A powerful Viking chieftain and naval commander, Björn and his brother Hastein conducted many (mostly successful) raids in France in a continuation of the tradition initiated by their (possibly adoptive) father Ragnar Lodbrok. In 860, Björn led a large Viking raid into the Mediterranean. After raiding down the Spanish coast and fighting their way through Gibraltar, Björn and Hastein pillaged the south of France, where his fleet over-wintered, before landing in Italy where they captured the coastal city of Pisa. They proceeded inland to the town of Luna, which they believed to be Rome at the time, but Björn found himself unable to breach the town walls.