At the apex of his rhetorical career, with the delivery of the Panegyricus of Trajan, Pliny embarked on an ambitious project: collecting and releasing a selection of his private epistles. Little is known about the dating of the publication, and no critical consensus has been reached on its phases. Based on internal chronological references, however, the epistles themselves can be confidently located some time between 98 and Pliny's hurried departure for Bithynia in 109 or later. In its final form, the collection totals 247 letters, organized into nine books. Macroscopically, the letters give a strong impression of authenticity and immediacy. They are what we are accustomed to call private letters: however stylistically (re-)elaborated, they display all the features we expect of a real correspondence. They are addressed to a variety of correspondents, all duly indicated in the opening salutatio, and encompass a wide range of topics. In subject-matter, they vary from the most immediately transparent notes commenting on the daily transactions among Pliny's familiares (friends and family) to the most stylistically and rhetorically engaged reports on notable biographical, social and political events, along with the occasional philosophical meditation. The variety in addressee, subject-matter and style is balanced by one sole factor, the constant presence of the sender's epistolographic persona.