Unfortunately, Edmund had been wounded in the most recent Battle of Assandun. The historian Henry of Huntingdon, writing a century later, says Edmund died in Oxford from multiple stab wounds while using the privy. It is more likely that he died in London, on 30 November 1016. More contemporary records like the Encomium Emmae Reginae ("Encomium of Queen Emma") do not mention murder. Death from battle wounds is a more likely outcome. His burial place at Glastonbury Abbey was destroyed during Henry VIII's Dissolution of the Monasteries, so an examination of his remains is impossible.
Cnut was now King of England. Archbishop of Canterbury Lyfing crowned him in 1017. As King of England with ties to Denmark, he made sure that both Danes and Anglo-Saxons flourished, with exceptions: he had to make sure that there would be no challenges to his throne. The children of Edmund Ironside, and his father Æthelred's other children, fled to Normandy. Edmund's brother Eadwig Ætheling fled, but was followed and killed by Cnut's men.
Cnut then wed Emma of Normandy, Æthelred's widow. He was, of course, already married to Ælfgifu of Northampton, but this caused no problem. Setting aside one wife for another was common, especially if the first marriage was not by a Christian ceremony. Ælfgifu remained part of the family and the royal court, and her sons by Cnut still had standing.
There was another piece of business he had to conclude: paying off the thousands of mercenaries he had hired to help him conquer England. They had joined for the promise of payment once the country was secure. Cnut collected a Danegeld of £72,000, and a further £10,500 from London alone. He paid his army and sent most of them away, keeping some ships and men. He then used an annual tax called heregeld ("army gold") to maintain a standing army.
Cnut ruled England for about two decades, and we'll go into some of his accomplishments (and his orchestrated failure) next time.