Princess Sophie Frederika Mathilde of Wurttemberg (1818-1877) married William, Prince of Orange (and her first cousin) in 1839. Sophie (as she was known) was alert, well-educated, and ambitious, far the intellectual superior of her husband; as the great-granddaughter of Catherine the Great of Russia, she may have aspired to play an important role in guiding the affairs of the House of Orange. This was not to be. After the birth of two sons, her relations with her husband cooled, and with a few important exceptions she became isolated from the other members of the family at the Hague. Partly to overcome the resulting personal and intellectual isolation she turned to an extensive correspondence with heads of state, royal relatives, aristocratic acquaintances, political leaders, and intellectual figures. Family difficulties continued and even increased after William ascended the throne in 1849. Sophie met her friend and confidant Marina Dora Spading, Lady Malt, when the latter was at the Hague with her diplomat husband in 1842. A lifelong friendship ensued, although they saw each other only infrequently thereafter. Sophie’s letters to Lady Malt are an extraordinary combination of comments on her personal situation and shrewd analyses of the European political arena. This selection of her surviving correspondence is opinionated, frank, and perceptive, and her letters are a unique commentary on the affairs of the Europe of the mid-nineteenth century.