The long eighteenth century is characterized as a watershed moment for women's increased engagement as both readers and writers. Key to understanding that engagement is the phenomenon of the personal library collection. Studying the development of women's personal libraries unearths hidden legacies of reading and reception that revise and extend existing histories. This essay explores the collecting practices and libraries of an aristocratic mother and daughter: Frances Seymour, the Countess of Hertford, later Duchess of Somerset (1699–1754); and Elizabeth Percy, the Duchess of Northumberland (1716–1776). Using six manuscript library catalogs from the Northumberland Archives as a case study, it illuminates trends and issues in the study of ...