Succeeding Æethelstan as King of the English was his half-brother, Edmund I, also called Edmund the Elder and Edmund the Magnificent.

Edmund was born to Edward the Elder and his third wife, Eadgifu, in 921. Edmund was 18 when he took over as king on the death of Æthelstan, in 939. Not longer becoming king, Edmund married Ælfgith. She died five years later, and he married Æthelflæd.

Edmund is known for responding quickly and efficiently to repeated threats from Danish invaders. Wasting no time on a new opportunity, the Danish leader Olaf Guthfrithson conquered York and then raided into the Midlands. Edmund led a force in retaliation to Leicester, and the resulting confrontation resulted in a treaty that granted Olaf the lands north of Watling Street on the condition that he recognize Edmund as his overlord. Also in this treaty, the two rulers agreed to be each other's heirs. If Edmund had died before Olaf, then a Dane would have been on the throne that much earlier. Olaf died in 941, and Edmund set about retaking Olaf's lands. He did so, conquering Olaf's successors in the process.

Edmund didn't stop there, continuing his march north. He conquered Strathclyde, in retaliation for that monarch's support for the Danes in York. Donald mac Donald had no chance to hand over the kingdom, which Edmund promptly ceded to King Malcolm I of Scotland. Edmund's condition for this handover of territory, of course, was the familiar one: recognize Edmund as overlord. In this way, Edmund maintained the stability atop the hierarchy, reigning as King of the English in the same way that Æthelstan had.

With his domestic affairs rather peaceful, Edmund turned to affairs on Continental Europe. At one point, he successfully negotiated the release of his nephew, Louis IV of France, who had been taken by Hugh the Great of France. Further, Edmund saw to it that Louis was restored to the throne.

Edmund died a sudden death, on May 26, 946. A thief named Leofa, whom Edmund had exiled for his crimes, killed the king while he was attending mass in Pucklechurch, Gloucestershire. Edmund as buried at Glastonbury Abbey. He had sons, but they were too young to rule. As a result, the throne passed to his brother Eadred.