Bjorn acquired the name Ironside from the demonstrated strength of his limbs in the many combats he faced in his raiding career. Bjorn was commander of a large Viking fleet of ships with which he raided France, England, Iberia, and Italy.

Bjorn's life is described in many early legends: Icelandic, Danish, Frankish, and Old English sagas. All these venerable writings describe a warrior who would eventually become King of Sweden. However, each of the tales describe a different, though colorful life.