thelfleda or Æthelflæd, d. 918, daughter of King Alfred the Great of Wessex and wife of Æthelred, ealdorman of Mercia. After her husband's death in 911 she reigned alone and was known as the Lady of the Mercians. Her energetic prosecution of resistance against the Danes and her wise government, both before and after her husbands death, won her the reputation as one of the most remarkable women in English history. [The Illustrated Columbia Encyclopedia, 3rd ed., 1969]
Ethelfleda (? d. 918), daughter of King Alfred. As Lady of the Mercians, and sole ruler on her husbands death (?912), she besieged and took Derby and Leicester, and finally made the Danes acknowledge her sway. [World Wide Illustrated Encyclopedia, 1935]
Died before Father, unmarried and without issue. {Burkes Peerage} [GADD.GED]