'lady of the Mercians' (d.918). Daughter of Alfred the Great, Aethelflaed was married to Ealdorman Aerheled of Mercia in 884. She rued Mercia jointly with ther husnband, and after his death in 911 ruled alone for the remainder of her life. She gave permission for the Viking Ingamund to settle on the Wirral c.902 and refortified Chester in 907. after he attacked it c 905. She founded burhs at Eddisbury and Runcorn to block Viking expansion south of the River Mersey. From 912 she cooperated closely with her brother Edward the Elder, king of Wessex, in his campaign to conquer the Danelaw. In 917 Aethelflaed captured Derby, and in 918 Leicester surrendered to her. In the same year the Danes of York offered to submit to her, but she died before the offer could be acted upon. She was briefly succeeded by her daughter Aelfwynn, but in 919 Edward formally annexed Mercia to Wessex.
Notes from Encyclopaedia of the Viking Age by John Haywood. Thames
& Hudson 2000. p 19