In mid-1500s France, Martin Guerre is determined to free his father, the Comte de Montgomery, from an unjust prison sentence. Montgomery had dared to love the King's mistress, Diana de Poitiers; to prevent King Henry II from discovering her indiscretion, Poitiers had arranged to have Montgomery put away for life, under conditions where no one is allowed to speak to him--and no one knows his true identity. But Guerre discovers that his father still lives, and with his half-brother, the heir to the title, will do anything to free his long-lost parent--even take the city of Calais by force from its English occupiers. The King's daughter, Diana de France, supports Guerre, because she loves his half-brother. As the political war between the two Dianas reaches its climax, Martin is determined to force Henry into the open. But Henry has his own plans Another first-rate historical drama by a master plotter