The Axe of Ragnar Lothbrok is the weapon favored by Ragnar. He has used this axe from when he was a farmer to when he became king.
While it is sometimes not possible to tell which Viking axes were used as tools and which ones were used as weapons, some axes are clearly meant to be weapons. All the axes of the Viking Age were made from iron, but some are more elaborately decorated than others. Like most other Scandinavian weaponry, axes were often given names. According to the Prose Edda, axes were often named after she-trolls.