William Hunt, Dictionary of National Biography… (1889)
“ After Æthelred's death she continued to rule Mercia, with the title of the ‘Lady of the Mercians,’ but the king joined London and Oxford, with the lands pertaining to them, to Wessex. Æthelflæd now set herself to secure Mercia against the attacks of the Danes and Northmen by building fortresses which would hinder them from entering the country from North Wales, where they found allies, or by the principal roads that led into central England. ”
