In 913, central England was a battleground. Viking armies still held much of the Danelaw, and the old kingdom of Mercia stood between them and Alfred the Great’s emerging “England.” Ruling Mercia was Alfred’s eldest daughter, Æthelflæd. Widowed after the death of her husband, Lord Æthelred, she did something astonishing for her time: she ruled on her own, known in the chronicles as “Lady of the Mercians.” Instead of retreating into piety, Æthelflæd went on the offensive. Working with her brother