Elisabeth, Countess Palatine (1618–1680)

Princess Elisabeth, daughter of the Elector Palatine Frederick V and Elizabeth Stuart ("The Winter Queen") of Bohemia, never married. She carried on a lengthy correspondence with René Descartes on moral and philosophical ideas, and after his death, became the abbess of the Protestant Abbey of Herford in Saxony, where she offered refuge to many political refugees. She was a scholar and philosopher, and besides Descartes influenced some other key figures of the 17th century, including William Penn.