Harold, the son of Canute and Aelfgiu of Northampton, was born in about 1016.
In 1035 Harold became regent of England on the death of his father, Canute. His half-brother, Hardicanute, succeeded as king of England but left the throne in charge of his brother, Harold, while he was detained in Denmark.
Harold showed little mercy in his rule as regent. When Alfred Atheling of Wessex made a bid for the English throne, he was brutally murdered in Ely Cathedral. Harold then ignored Hardicanute's inheritance and proclaimed himself King of England. At the same time he sent his step mother, Emma, mother of Hardicanute, into exile.
In 1040 Harold died at Oxford and his body was buried at the old cathedral in Westminster. When Hardicanute arrived in England, he ordered Harold's body dug up, decapitated, and thrown into a fen. Harold's body was recovered later and given a proper burial in St Clement Danes church, London.
Harold was succeeded by his half-brother, Hardicanute.