Æthelstan or Athelstan (c. 893/895 – 27 October 939) is King of the Anglo-Saxons from 924 to 927 and King of the English from 927 to 939.

He is the son of King Edward the Elder and his first wife, Ecgwynn.

Historians regard him as the first king of England and one of the greatest Anglo-Saxon kings.

He never marries, and is succeeded by his half-brother, Edmund.

When Edward dies in July 924, Æthelstan is accepted by the Mercians as king.

His half-brother Ælfweard may have been recognized as king in Wessex, but dies within weeks of their father.

Æthelstan still encounters resistance in Wessex for several months, and is not crowned until September 925.

In 927, he conquers the last remaining Viking kingdom, York, making him the first Anglo-Saxon ruler of the whole of England.

In 934 he invades Scotland and forces King Constantine of Scotland to submit to him, but Æthelstan's rule is resented by the Scots and Vikings, and in 937 they invade England.

Æthelstan defeats them at the Battle of Brunanburh, a victory that gives him great prestige both in the British Isles and on the continent.

However, after his death in 939, the Vikings seize back control of York, and it is not finally reconquered until 954.

Æthelstan centralizes government; he increases control over the production of charters and summons leading figures from distant areas to his councils.

These meetings are also attended by rulers from outside his territory, especially Welsh princes, who thus acknowledge his overlordship.

More legal texts survive from his reign than from any other tenth-century king; they show his concern for social order and especially for the threat posed to it by widespread robberies.

His legal reforms build on and are commensurate with those of his grandfather, Alfred.

Æthelstan is one of the most religious West Saxon kings, and has a reputation for collecting relics and founding churches.

His household is the center of English learning during his reign.

No other West Saxon king plays as important a role in European politics as Æthelstan, and he arranges the marriages of several sisters to continental rulers.