Æthelstan behaves as a Mercian king in early 925, describing himself as Rex Anglorum in a charter relating to land in Derbyshire, witnessed only by Mercian bishops.

He does not appear to have established his authority in Wessex until the middle of the year.

In the view of David Dumville and Janet Nelson he may have agreed not marry or have heirs in order to gain acceptance.

However, Sarah Foot suggested that he probably had a religious devotion to chastity as a way of life.

The coronation of Æthelstan takes place on September 4, 925 at Kingston upon Thames, perhaps due to its symbolic location on the border between Wessex and Mercia.

He is crowned by the Archbishop of Canterbury, Athelm, who probably designed or organized a new ordo (religious order of service) in which the king wore a crown for the first time instead of a helmet.

The new ordo is influenced by West Frankish liturgy and in turn will become one of the sources of the medieval French ordo.

Opposition seems to have continued even after the coronation.

According to William of Malmesbury, an otherwise unknown nobleman called Alfred plotted to blind Æthelstan on account of his supposed illegitimacy, although it is unknown whether he aimed to make himself king or was acting on behalf of Edwin, Ælfweard's younger brother.

Blinding would have been a disability that made Æthelstan ineligible for kingship without incurring the odium attached to murder.