at the
Göta älv river in modern-day Sweden. Illustration by
Halfdan Egedius. The political agreement between Harthacnut and
Magnus the Good included the appointment of Magnus as Harthacnut's heir. At the time, this arrangement applied only to the throne of Denmark. According to the
Heimskringla, when Harthacnut died, Magnus extended his claim to England. He reportedly sent a letter to
Edward the Confessor, asserting his claim to the English throne and threatening invasion. Magnus’s own heir,
Harald Hardrada, would later pursue this claim as well. Both considered themselves legal successors to Harthacnut. The
Fagrskinna records Magnus proclaiming: "I will take possession of all the Danish empire or else die in the attempt." According to the
Encomium Emmae Reginae, Edward had already served as co-ruler of England since 1041. The work emphasizes Harthacnut, Edward, and Emma acting as a trinity of rulers, in emulation of the
Holy Trinity. Edward, by surviving Harthacnut, would automatically inherit the kingship. The
Heimskringla depicts Edward presenting himself as brother and legal heir to both Harold Harefoot and Harthacnut, noting that he had already secured "
the support of all the people of the country". Unstated in these accounts is that Edward’s eventual marriage to
Edith of Wessex strengthened his claim by gaining the political backing of her father,
Godwin, Earl of Wessex, and an additional connection to Cnut, as she was a niece of the king. The
Fagrskinna emphasizes Edward’s strong familial claim: as the son of
Æthelred the Unready and Emma of Normandy, half-brother of Harthacnut, stepbrother of Harold Harefoot, and stepson of Cnut, he was closely tied to multiple royal lines. England’s leading nobles had already acknowledged him as king, and he was consecrated by an archbishop. He was thus widely regarded as the legitimate ruler. According to the saga, Magnus was warned: "You can never be called king in England, and you will never be granted any allegiance there before you put an end to my life." This reportedly caused Magnus to doubt the strength of his claim. The planned marriage between
Gunhilda of Denmark, Harthacnut’s sister, and
Henry III, Holy Roman Emperor was intended to allow their descendants to claim the Danish throne, and potentially the English throne. From Henry’s perspective, it was likely designed to give the
Holy Roman Empire influence over Denmark and the western Baltic region. Gunhilda died in 1038 with no known sons. Her only daughter,
Beatrice I, Abbess of Quedlinburg, never married. == Reputation ==