Athelstan became king in 924. He was the son of Edward the Elder who ruled 899-924 and the grandson of Alfred the Great. We do not know exactly when Athelstan was born but historians consider that the year was probably around 894 making him about thirty years old at his accession. We know nothing about his place of birth and very little about his early childhood. According to a later tradition Athelstan was a favourite of his grandfather.

William of Malmesbury told the story of how King Alfred honoured his grandson as a child, investing him with the gift of a scarlet cloak, a belt set with gems, and a Saxon sword with a gilded scabbard. Athelstan can have been no more than five or six years old at the time because Alfred died in 899.