Athelstan (born 894, died 27 October 939) was King of the Anglo-Saxons from 924 to 927 and King of the English from 927 to his death in 939.
He was the son of King Edward the Elder and his first wife, Ecgwynn. Modern historians regard him as the first King of England and one of the "greatest Anglo-Saxon kings". He never married and had no children; he was succeeded by his half-brother, Edmund I.

On the death of his father, Edward the Elder, in 924, Athelstan was elected king of Wessex and Mercia, where he had been brought up by his aunt, Aethelflaed, Lady of the Mercians. Crowned king of the whole country at Kingston on Sept. 4, 925, he proceeded to establish boundaries and rule firmly. He annexed the Viking kingdom of York in 927. His dominion was significantly challenged in 937 when Constantine of the Scots, Owain of Strathclyde, and Olaf Guthfrithson, claimant of the kingdom of York, joined forces and invaded England. They were routed at Brunanburh.

Six of Athelstan’s extant codes of law reveal stern efforts to suppress theft and punish corruption. They are notable in containing provisions intended to comfort the destitute and mitigate the punishment of young offenders. The form and language of his many documents suggest the presence of a corps of skilled clerks staffed by the cathedral of Winchester. Both his charters and the silver coinage he issued through strictly controlled regional mints bore the proud title Rex totius Britanniae (“King of all Britain”).