Athelstan was the son of Edward the Elder, and grandson of Alfred the Great. His father succeeded, after some difficulty, to the Kingdom of the Anglo-Saxons formed by Alfred. His father had also been the King of Mercia. When Edward died Athelstan quickly became King of Mercia but he was not immediately accepted as King of England. His brother, Ælfweard, had more support in England but died soon after Edward. This made it easier for Athelstan to become king.