Canute was the younger son of Sweyn Forkbeard (c. 960–1014) and Princess Gunhild, and the grandson of Harold Bluetooth, king of the Danes. In 1013 Canute joined Sweyn on his third attempt to invade England. Sweyn forced the incompetent King Ethelred II the Unready (968–1016) to escape to the homeland of his second wife, Emma (c. 988–1052), daughter of Duke Richard of Normandy.

The demoralized English Witanagemot (the governing assembly) acknowledged Sweyn as king. Upon Sweyn’s death in 1014, the inexperienced 18-year-old Canute fled to Denmark when Ethelred returned to England, reclaimed the throne, and was crowned on April 23, 1016. Ethelred died a few months later and his eldest surviving son, Edmund Ironside (c. 980–1016), was chosen as king by the Londoners, although the general population outside of London wanted Canute as king.

Canute vanquished Edmund at the Battle of Assandurea (Ashingdon) on October 18, 1016. Edmund and Canute agreed to divide the country; Edmund took present-day Wessex, East Anglia, Essex, and London and Canute received all the other territories. This agreement ended the civil war. Edmund died on November 30, 1016. The Witangemot allowed Canute to succeed to the throne as king of a united England.

Canute’s reign from 1016 to 1035 was initially problematic and engendered a considerable amount of bloodshed because of some resistance. Ultimately he was successful because he was deemed a Christian rather than a conqueror. Canute capably and fairly utilized the wealth of the immensely prosperous country. He gained the support of the aristocracy and realized his strength would lie in a strong alliance with England.

Moreover, he respected England’s Anglo-Saxon customs and institutions. Canute issued dooms, supported the church by erecting churches, granted the clergy lands, gave them considerable treasure, and a peaceful environment in their monasteries. He brought unity to a land previously torn apart by centuries of Viking invasions, thus obtaining both English and Anglo-Danish support.

Canute’s greatest contribution to the administrative development of England was arbitrarily to declare the administrative districts of Northumbria, Wessex, Mercia, and East Anglia. He placed them under the authority of a Danish earl, or jarl, who were under Canute’s firm control.

After banishing his first wife and their son Sweyn, Canute married the strong-minded Emma, widow of Ethelread the Unready. They had a son, Harthacanute (1018–42), and a daughter, Gunhild, who would later marry Holy Roman Emperor Henry III. His other son was Harold Harefoot (c. 1016–40) by his mistress, Elfgifu of Northampton.

Canute also introduced trained infantrymen known as housecarls. These elite, honored, and privileged men formed the basis of the future English army and soon became wealthy—the English people were heavily taxed to support them. The housecarls were an entity unto themselves; they had their own regulations, judicial system, and huge arsenal of weapons.

Canute promulgated a revised Anglo-Saxon legal code that respected Anglo-Saxon continuity. Economically, many towns emerged in England because of the vigorous North Sea trade. Socially the English people were content with their capable ruler. Harold, Canute’s brother, died in 1018 and Canute became king of Denmark. He was equally capable of ruling in Denmark as in England.

Canute issued Denmark’s first national coinage, separated the clergy from the realm, and declared peace and friendship between the Danes and the English. However England was forced to pay a Danegeld sum (tax) of £82,500 to Denmark. In 1027 Canute made a pilgrimage to Rome and visited holy places, sanctuaries, and the tombs of various apostles.

He also attended the coronation of Holy Roman Emperor Conrad II (c. 990–1039). Conrad asked Canute to administer parts of present-day Germany. Canute gained control over the Danish parts of Norway in 1028 when the Norwegian nobles supported him in expelling Olaf II (Saint Olaf, 995–1030). Canute made his son Sweyn subking in 1029 with Sweyn’s mother acting as regent. They were driven out in 1035.

Ultimately Canute’s huge Scandinavian empire was only held together by a fragile allegiance and was financially supported by a bountiful England. Canute died in 1035 and was buried at Winchester. He had failed to leave a succession provision and his sons initially jointly ruled. Harthacanute took power in Denmark.

Harold proclaimed himself king of England but died five years later after a calamitous reign. Harthacanute then took over as king of England. Canute’s North Sea kingdom fell apart and his line ended in 1042. At Harthacanute’s suggestion the Witangemot chose Edward the Confessor (1003–66) as its king in 1043.