Æthelhelm was the eldest son of Æthelred the Unready, the last Anglo-Saxon king of England. Æthelhelm was born around 990 and died in 1014, before his father. He was never king, and his younger brother Edmund Ironside succeeded Æthelred after his death in 1016.
Æthelred I of Wessex: The Untold Chapter of English History