The partly legendary Danish chronicle of Saxo Grammaticus, "Gesta Danorum" (c. 1200), is the first text to mention Björn Ironside as a King of Sweden. According to Saxo, Ragnar Lodbrok had a quarrel with the recently elevated ruler of the Swedes, Sörle. He therefore invaded the Swedish lands in company with his sons Björn, Fridleif and Radbard. Before battle had broken out, the opposing sides agreed to settle the matter through a combat. Ragnar and his three sons met the renowned champion Starkad and his seven sons in the sight of the two armies. "Björn, having inflicted great slaughter on the foe without hurt to himself, gained from the strength of his sides, which were like iron, a perpetual name Ironside". Ragnar and his sons slew their eight opponents, after which their troops fell on Sörle and his army and annihilated them. Ragnar then "presented Björn with the lordship of Sweden for his conspicuous bravery and service." Later on, another son of Ragnar, Ubbe, colluded with his maternal grandfather Esbjörn and conspired against Ragnar. Esbjörn sent envoys to Björn in Sweden to drum up support for a rebellion, but Björn refused to listen. Instead, he hanged the envoys while their party were slaughtered by the Swedes. Shortly afterwards Esbjörn was slain in a sea battle, and Ubbe was captured after a heroic resistance. In due time Ragnar appointed Björn regent of Norway, while Sweden was handed over to another son, Eric Weatherhat. After the death of Ragnar, Björn and his brothers attacked Ella in England with 400 ships and killed him. He then went back to his Swedish kingdom, but intervened in Denmark when the Danes rose against the rule of Ragnar's sons. With a fleet of 1,700 ships, he and his brothers crushed the insurgents at Slesvig. This is the last we hear about Björn Ironside in the "Gesta Danorum".