A History of the British Monarchy/Viking Rulers
England's line of Viking kings spans a dynasty of three generations. It was founded in 1013 by Sweyn Forkbeard, King of Denmark. He was the son of Harald Bluetooth, who after years of conflict, wrested the throne of England from the ineffectual native Saxon king Ethelred II the Redeless (978-1016).
Sweyn was followed by his son Canute, who was known as the Great. He was the ablest of his line. Sweyn converted to Christianity and married Ethelred II's widow, Emma of Normandy (c. 985 – 6 March 1052), the daughter of Richard I, Duke of Normandy.
Canute's two sons, the illegitimate Harald Harefoot (1037–1040) and Hardicanute or Harthacnut (1040–1042), his son by his marriage to Emma, reigned after him. Both were antagonistic toward one another.
On the death of Hardicanute in 1042, the old Saxon line of Wessex was restored in the person of Ethelred's son, Edward I, the Confessor (1042–1066).