Edmund I (or Eadmund) 922 – May 26 946), called the Elder, the Deed-Doer, or the Just, was King of England from 939 until his death. He was a son of Edward the Elder and half-brother of Athelstan.

Athelstan died on October 27 939, and Edmund succeeded him as king. Shortly after his proclamation as king he had to face several military threats. King Olaf I of Dublin conquered Northumbria and invaded the Midlands. When Olaf died in 942 Edmund reconquered the Midlands. In 943 he became the god-father of King Olaf of York. In 944, Edmund was successful in reconquering Northumbria. In the same year his ally Olaf of York lost his throne and left for Dublin in Ireland. Olaf became the king of Dublin as Olaf Cuaran and continued to be allied to his god-father. In 945 Edmund conquered Strathclyde but conceded his rights on the territory to King Malcolm I of Scotland. In exchange they signed a treaty of mutual military support. Edmund thus established a policy of safe borders and peaceful relationships with Scotland. During his reign, the revival of monasteries in England began.

Edmund was murdered in 946 by Leofa, an exiled thief. He had been having a party in Pucklechurch, when he spotted Leofa in the crowd. After the outlaw refused to leave, the king and his advisors fought Leofa. Edmund and Leofa were both killed. He was succeeded as king by his brother Edred, king from 946 until 955.

Edmund's sons later ruled England as: *Edwy of England, King from 955 until 957, king of only Wessex and Kingdom of Kent from 957 until his death on October 1 959. *Edgar of England, king of only Mercia and Northumbria from 957 until his brother's death in 959, then king of England from 959 until 975.

For a more complete genealogy including ancestors and descendants, see House of Wessex family tree.