Was the eldest son of King Canute II and Emma of Normandy and was therefore the heir to the English crown. He had been proclaimed king of Denmark in 1028 but when Canute died in 1035 Hardecanute was defending his land in Denmark. In his absence his illegitimate half-brother, Harold Harefoot was crowned King Harold I of England in 1037. Naturally there was a struggle between the two brothers that only ended on the death of Harold (17June 1040). Harthacnut sailed to England with a large fleet and was immediately accepted as king.

Harthacnut was a harsh and intolerant king who had Harold's body exhumed, beheaded and flung into a bog. Determined to defend his Danish kingdom he needed a huge navy and massively increased the English taxes. This was very unpopular and the citizens of Worcester killed two of the king's tax collectors in 1041. Harthacnut's revenge was swift and ruthless and his forces ravaged the town and county. (This is the period that the legend of Lady Godiva belongs.) Harthacnut died, apparently of a fit but poison cannot be ruled out, after drinking heavily at a wedding party in Lambeth on the 8th June 1042. He was unmarried, with no children and the English crown passed to half-brother Edward the Confessor.

In the late 18th century George Steevens (1736-1800) a Shakespearian commentator and well known for playing practical jokes, often malicious, hoaxed the Society of Antiquaries with a tombstone he said had been dug up at Kennington but really engraved with an Anglo Saxon inscription of his own invention.