Alfred was married to Ealhswith in 868. She was the daughter of a Mercian ealdorman named Æthelred Mucel and her mother was Eadburh, who was a member of the Mercian royal family. The marriage would have been done in order to lay the groundwork for an alliance between the two kingdoms at a time when Mercia was threatened by Vikings in Nottingham. Alfred had at least five legitimate children. The first child was Æthelflæd who was born around 869, followed by Edward, Æthelgifu, Ælfthryth and Æthelweard. Æthelflæd would go to become a revered figure, marrying Æthelred, Lord of Mercia in the 880s. She went on to rule Mercia as 'Lady of the Mercians' from 911, when Æthelred died to her death in 918. On Alfred’s death Ealhswith was left two very significant estates to Alfred; an estate in Wantage and one in Edington. She died in 902.

A minature of Edward, after he had inherited the crown following Alfred's death

Ealhswith (left) and Æthelflæd (right) as shown in a 13th Century document made for Abingdon Abbey
(Public domain)