Canute II (also Cnut or Knut), called The Great (c. 994-1035), king of England (1016-1035), Denmark (1018-1035), and Norway (1028-1035). Canute, the son of Sweyn I Forkbeard, king of the Danes, conquered England in 1013. When his father died the following year, he was proclaimed king of England by his Danish warriors. However, the witenagemot, an advisory body to the Anglo-Saxon kings, reinstated King Ethelred II, and Canute fled. He returned in 1015 and soon subjugated all of England, except London. After Ethelred's death in 1016, the Londoners named his son, Edmund II, king. During an ensuing struggle, the Londoners were defeated at Ashingdon, Essex, in October 1016. The following month Edmund died and Canute emerged the undisputed king. A wise and effective ruler, he maintained peace with the Continental powers. He married King Ethelred's widow, Emma of Normandy, supported the Church, and in 1027 went to Rome for the coronation of Holy Roman Emperor Conrad II. For administrative purposes he divided England into the four earldoms of Mercia, Northumberland, Wessex, and East Anglia.

Canute continued to reside in England even after he inherited the crown of Denmark in 1018. He soon began his conflict with Olaf II of Norway, whose realm he claimed. Forcing Olaf into exile in 1028, Canute installed his young son, Sweyn, to govern Norway; after Olaf's fall at Stiklestad in 1030 his rule was unchallenged. Canute's North Sea empire fell apart after his death. Two sons separately ascended the thrones of England and Denmark, while the son of Olaf II succeeded in Norway.