Ivar Ragnarsson or Ivar the Boneless (inn beinlausi) as he was curiously referred to, was a Viking warlord and a man of exceptional cruelty and ferocity, he was the son of Ragnar Lodbrok and Aslaug Sigurdsdottir.
Viking History (Denmark). 'The Vikings were not just plunderers but successful traders, extraordinary mariners and insatiable explorers. Getting a feel for the Viking era is easy, whether visiting the ship-burial ground of Ladby, the Viking forts of Zealand, the longship workshops at Roskilde or the museums that seek to re-create the era with live re-enactments.' http://www.lonelyplanet.com/denmark