Hij is getrouwd met Ealdgyth (Edith) Algitha of East Anglia.in het jaar 1015 te Malmsbury, Wiltshire, hij was toen 26 jaar oud.
Edmund Ironside or Eadmund, surnamed "Ironside" for his efforts to fend off the Danish invasion led by King Canute, was King of England from April 23 to November 30, 1016.Edmund was the second son of King Æthelred II (also known as Ethelred the Unready) and his first wife, Ælfgifu of Northumbria. He had three brothers, the elder being Æthelstan, and the younger two being Eadred and Ecgbert. His mother was dead by 996, after which his father remarried, this time to Emma of Normandy.Æthelstan died in 1014, leaving Edmund as heir. A power-struggle began between Edmund and his father, and in 1015 King Æthelred had two of Edmund's allies, Sigeferth and Morcar, executed. Edmund then took Sigeferth's widow, Ældgyth, from the nunnery where she had been imprisoned and married her in defiance of his father. During this time, Canute the Great attacked England with his forces. In 1016 Edmund staged a rebellion in conjunction with Earl Uhtred of Northumbria, but after Uhtred deserted him and submitted to Canute, Edmund was reconciled with his father.Æthelred II, who had earlier been stricken ill, died on April 23, 1016. Edmund succeeded to the throne and mounted a last-ditch effort to revive the defence of England. While the Danes laid siege to London, Edmund headed for Wessex, where he gathered an army. When the Danes pursued him he fought them to a standstill. He then raised a renewed Danish siege of London and won repeated victories over Canute. However, on October 18 Canute decisively defeated him at the Battle of Ashingdon in Essex. After the battle the two kings negotiated a peace in which Edmund kept Wessex while Canute held the lands north of the River Thames. In addition, they agreed that if one of them should perish, territories belonging to the deceased would be ceded to the living.On November 30, 1016, King Edmund II died in Oxford or London and his territories were ceded to Canute who then became king of England. The cause of Edmund's death has never been clear, with many accounts listing natural causes, while others suggest that he was assassinated. Edmund was buried at Glastonbury Abbey in Somerset. His burial site is now lost. During the Dissolution of the Monasteries any remains of a monument or crypt were destroyed and the location of his body is unknown.Edmund had two children by Ældgyth: Edward the Exile and Edmund, who both were sent by Canute the Great to Sweden, in order to be murdered but were sent from there to Kiev, ending up in Hungary.