The diary, as a first person literary genre, remains difficult to differentiate from its counterparts. The earliest diaries written in French date from the mid-eighteenth century when the concept of expression of the self was just emerging. Six diaries of Catherine de Sévery (1741-1796), an eighteenth century aristocrat living in Lausanne, not yet part of Switzerland, allow the readers to discover this emergence of the self while in the same time get a picture of the society in which she lived. Spread over forty years of her life, these diaries cover a variety of topics including health, political events, customs, and family relationships. Related to Isabelle de Charrière and Benjamin Constant, Catherine de Sévery likewise had close ties with British historian Edward Gibbon and physician Samuel Tissot . Containing numerous references to literary works, these diaries provide a rich source of information on the influence of the Enlightenment in the Pays de Vaud.