Aelgifu of Northampton, also known as Alfgifu, Alfgitha, Eilfgiva, Aelfgyfu, Aelfgiuae (995 – 1040) was a daughter of Aelfhelm, Ealdorman of York, and the 'handfast' wife of Canute the Great, to whom she was bound in 1004. The two sons she had with Canute, Sven of Norway and Harald Harefoot, were to figure prominently in the empire which their father built in northern Europe, although sons of Emma of Normandy, Canute's court wife, and the twice Queen of England, were also claimants to the throne of her husband.
Canute sent Aelfgifu with their eldest son Sveinn to rule Norway in 1030. Their rule was so harsh that the Norwegians rebelled against them, and they were driven out in 1035, while Sveinn died of wounds in Denmark shortly after. In Norway this period is known as Aelfgifu's Time, remembered for heavy taxes.
Aelfgifu was determined that her second son should be the next English king, on the death of Canute in 1035. She bribed the noblemen to accept Harald as regent, while Harthacanute, Queen Emma's son by the late King of England, was away in Denmark, at war with the Norwegian king Magnus I of Norway, and the Swedes under their king Anund Jacob.
Aelfgifu was also part of a plot to murder Alfred Atheling, son of Queen Emma by Ethelred, who was on his way to see his mother after a long exile in Normandy. None could oppose Harald and the English supporters of his claim, especially after his Huscarls laid claim on the treasury, and he was crowned King of England in 1037. Aelfgifu fell into obscurity after Harald's death from a stroke in 1040 and the crowning of Harthacanute, the legitimate heir to Canute and also the King of Denmark.