Historian Fox offers this first dual biography of the daughters of Spain's Ferdinand and Isabella whose entwined royal relationships helped define the 15th- and 16th-century European political landscape.

From Matilda of Flanders, William the Conqueror's queen, to Elizabeth of York, the first Tudor consort, England's queens fashioned the nature of monarchy and influenced the direction of the state. Occupying a unique position in the mercurial, often violent world of medieval politics, these queens had to negotiate a role that combined tremendous influence with terrifying vulnerability. Lisa Hilton's illuminating new book explores the lives of the twenty...