At the Battle of Nesjar, in 1016, Olaf Haraldsson won the kingdom of Norway from the Danes. It was at some time after Eirkr left for England, and on the death of Svein while retreating to Sweden, maybe intent on returning to Norway with reinforcements, that Erikr's son Hakon went to join his father and support Cnut in England, too. Cnut's brother Harald may have been at Cnut's coronation, in 1016, returning to Denmark as its king, with part of the fleet, at some point thereafter. It is only certain, though, that there was an entry of his name, alongside Cnut's, in confraternity with Christ Church, Canterbury, in 1018. This is not conclusive, though, for the entry may have been made in Harald's absence, perhaps by the hand of Cnut himself, which means that, while it is usually thought that Harald died in 1018, it is unsure whether he was still alive at this point. Entry of his brother's name in the Canterbury codex may have been Cnut's attempt to make his vengeance for Harald's murder good with the Church. This may have been just a gesture for a soul to be under the protection of God. There is evidence Cnut was in battle with pirates in 1018, with his destruction of the crews of thirty ships, although it is unknown if this was off the English or Danish shores. He himself mentions troubles in his 1019 letter , written as the King of England and Denmark. These events can be seen, with plausibility, to be in connection with the death of Harald. Cnut says he dealt with dissenters to ensure Denmark was free to assist England:
Question: Who was Hakon's father?
Answer: Erikr