The fascinating history of Isabeau of Bavaria is a tale of two queens. During her lifetime, Isabeau, the long-suffering wife of mad King Charles VI of France, was respected and revered. After her death, she was reviled as an incompetent regent, depraved adulteress, and betrayer of the throne. Asserting that there is no historical support for this posthumous reputation, Tracy Adams returns Isabeau to her rightful place in history.

Adulteress and traitor--two charges long leveled against the queen--are the first subjects of Adam's reinterpretation of medieval French history. Scholars...