Harold's nickname "Harefoot" is first recorded as "Harefoh" or "Harefah" in the twelfth century in the history of Ely Abbey, and according to some late medieval chroniclers it meant that he was "fleet of foot".

Harold was originally buried in Westminster, but Harthacnut had his body dragged up and thrown into a fen adjacent to the river Thames, from where it was reportedly recovered by a fisherman and eventually reburied in a Danish cemetery in London.

Claiming that Ælfgifu wanted to have a son by the king but was unable to, she secretly adopted the newborn children of strangers and pretended to have given birth to them.

21st century author Harriet O'Brien doubts Cnut, the shrewd politician who "masterminded the bloodless takeover of Norway", could have been deceived in such a way.

She suspects the tale started out as a popular myth, or intentional defamation presumably tailored by Emma of Normandy, the other wife of Cnut and rival to Ælfgifu.

England's magnates[b] favored the idea of installing Harold Harefoot temporarily as regent or joint monarch, due to the difficulty of Harthacnut's absence, and despite the opposition of Godwin, the Earl of Wessex, and the Queen, he eventually wore the crown.

The Encomium Emmae Reginae also describes Edward the Confessor and Alfred Aetheling as the sons of Canute, though the modern term would be step-sons.

[4] The Anglo-Saxon Chronicle ignores the existence of Svein, or his claim to the throne, which Howard considers as evidence of the relative entries being unreliable, of failing to give a complete picture.

On this occasion Immo, a priest serving at the court of the Holy Roman Empire, wrote a letter to Azecho, Bishop of Worms.

It included information on the situation in England, with messengers from there reporting that Ælfgifu was gaining the support of the leading aristocrats through pleas and bribery, binding them to herself and Harold by oaths of loyalty.

"[10] With the north at least on Harold's side, in adherence to the terms of a deal, which Godwin was part of, Emma was settled in Winchester, with Harthacnut's huscarls.

[4] Harold himself is somewhat obscure; the historian Frank Stenton considered it probable that his mother Ælfgifu was "the real ruler of England" for part or all of his reign.

[13] Kelly DeVries points out that during the High Middle Ages, royal succession in Northern Europe was determined by military power.

The eldest son of a king could have a superior right of inheritance but still lose the throne to a younger brother, or other junior claimant, possessing greater military support.

His decision to remain in Denmark probably points to him lacking sufficient support, though he would certainly wait for an opportunity to forcefully assert his claim and depose his half-brother.

[15][16] In 1036, Ælfred Ætheling, son of Emma by the long-dead Æthelred, returned to the kingdom from exile in the Duchy of Normandy with his brother Edward the Confessor, with some show of arms.

[18] Ian Howard argued that Emma not being involved in a major political manoeuvre would be "out of character for her", and the Encomium was probably trying to mask her responsibility for a blunder.

[4] William of Jumièges reports that earlier in 1036, Edward had conducted a successful raid of Southampton, managing to win a victory against the troops defending the city and then sailing back to Normandy "richly laden with booty", but the swift retreat confirms William's assessment that Edward would need a larger army to seriously claim the throne.

[17] With his bodyguard, according to the Anglo-Saxon Chronicle, Ælfred intended to visit his mother, Emma, in Winchester, but he may have made this journey for reasons other than a family reunion.

[3][11] The failed invasion shows that Harold Harefoot, as a son and successor to Cnut, had gained the support of Anglo-Danish nobility, which violently rejected the claims of Ælfred, Edward, and (by extension) the Aethelings.

[4] Harold died at Oxford on 17 March 1040,[16] just as Harthacnut was preparing an invasion force of Danes, and was buried at Westminster Abbey.

[20] A contradictory account in the Knýtlinga saga (13th century) reports Harold buried in the city of Morstr, alongside his half-brother Harthacnut and their father Cnut.

[15][25] Michael Evans points out that Harold was only one of several youthful kings of pre-Conquest England to die following short reigns.

Emma Mason speculates that Cnut had built a royal residence in the vicinity of the Abbey, or that Westminster held some significance to the Danish Kings of England, which would also explain why Harthacnut would not allow a usurper to be buried there.

The lack of detail in the Anglo-Saxon Chronicle implies that, for its compilers, the main point of interest was not the burial site, but the exhumation of the body.

[19] Harriet O'Brien theorises that the choice of location might simply reflect the political affiliation of the area of Westminster and nearby London, being a power base for Harold.

Ælfwine/Alboin is recorded in 1060 and 1062 in charters from the Abbey Church of Saint Foy in Conques, which mention him as son of "Heroldus rex fuit Anglorum" (Latin: Harold, who was king of the English People).

He proceeds to portray Harold as follows: "...He went astray from the qualities and conduct of his father King Cnut, for he cared not at all for knighthood, for courtesy, or for honour, but only for his own will...".

[29] The Knýtlinga saga (13th century) considers Harold Harefoot to be the oldest son of Cnut and Emma of Normandy, though its author frequently misrepresents family relationships.