Désirée by Annemarie Selinko

Désirée is a historical novel, in the form of a fictional diary, that tells the story of Désirée Clary, the daughter of a silk merchant from Marseille, who became Napoleon's first love, and later, through a set of extraordinary circumstances, Queen of Sweden. The major events of Napoleon's reign are told through her eyes. The book was made into a film starring Jean Simmons and Marlon Brando.