After the restoration of London, Alfred received the submission of "all the English people who were not under subjection to the Danes", and the alliance between Wessex and Mercia was cemented by the marriage of Æthelred to Alfred's oldest daughter, Æthelflæd. She is first recorded as Æthelred's wife in a charter of 887, but Keynes thinks that the marriage may have taken place two or three years earlier, and the historian Maggie Bailey dates it to between 882 and 887, with the most likely political context being the occupation of London in 886. Æthelred was probably much older than his wife. They had a daughter, Ælfwynn, and according to the twelfth century chronicler, William of Malmesbury, she was their only child. In King Alfred's will, drawn up in the 880s, Æthelred was left a sword worth 100 mancuses.