Björn "Ironside" Ragnarsson was a legendary Swedish king who presumably reigned during the 9th century. He is considered to be the founder and the first king of the Munsö dynasty, a protohistoric Scandinavian royal house whose early members of the 8th or 9th centuries are regarded as legendary while the late scions of the 10th and 11th centuries are known to be historical figures. According to legends, Björn was one of the sons of Ragnar Lothbrok, the near-mythical Danish and Swedish Viking hero and ruler, and his third wife, Aslaug. He grew up alongside his brothers and half-brothers and later ventured out of Sweden to conquer Zealand, Reidgotaland, Gotland, Öland and all the minor islands. He then spent a considerable period of his life at Lejre in Zealand. The legends further state that he and his brothers left Zealand to avenge their half-brothers who had been killed in Sweden. Björn also conducted raids in France and the Mediterranean. After their father was executed by Ælla, the king of Northumbria, England, Björn and his siblings launched a successful campaign against him. Ælla was ultimately captured and subjected to the blood eagle. Various Norse sagas name Björn’s several children, including Erik Björnsson, who was his immediate successor.
