For centuries before the rise of Constantine, letter writing had played a critical role in Roman social relations. Traditional Greek and Latin-speaking elites relied on letters to communicate shared culture, and to maintain webs of personal bonds. Elite men, such as Pliny the Younger, published letter collections to demonstrate their social reach. Philosophic and religious movements employed letter collections for these purposes, as well as the more focused goals of defining doctrine and community boundaries. Early Christian letter collections differ sharply from traditional elite Roman collections, in their stark moral expressions and demands for solidarity. Second and third century bishops, such as Ignatius of Antioch and Cyprian of Carthage, used letters to represent their community, and to paint themselves as figures of authority. It was late antiquity, however, that brought the collision of traditional elite and clerical epistolary practice, as larger numbers of educated elites embraced Christianity and assumed church office. And letter collections of the fourth and fifth centuries reflect a serious tension, between elite and early clerical social messaging, and the resultant patterns of relations. This paper explores the way epistolary social interactions were affected by holding clerical office, especially the role of bishop. The focus falls on two educated men whose collected letters span the times before and after their election as bishop. Basil of Caesarea had long used his letters to maintain friendships, bonds with school mates, and elite connections when he became priest and then bishop (in 370) of a familiar Cappadocian town. Synesius of Cyrene had relied on his letters to bond with fellow former courtiers, relatives, and devotees of philosophy when he was chosen as bishop of Ptolemais (in 410). Numerous biographies and monographs (including studies by Marrou, Bregman, Rousseau, Métivier, and Van Dam) have examined these men, with their divergent interests, circles of associates, and personal itineraries. But these very differences help to reveal the ways in which episcopal office redirected elite late Roman social lives. For this presentation, I explore two sorts of shifts that can be linked to the assumption of bishoprics. First I look at changes in the new bishops' social expressions – the phrases, cultural references, and other cues that signaled meaningful attachments with patrons, clients and friends. Second, I analyze shifts in the new bishops' pattern of social relations, the portion of social networks that can be traced from the epistolary exchange of social cues. This approach affords a fresh view of the two main subjects. Scholars have usually cast Basil as a firm convert, who abandoned his secular interests for asceticism, theology, and clerical duty. They have portrayed Synesius as eager to maintain philosophic and sophistic pursuits, and reluctant to embrace clerical life. But both men found rhetorical advantages and limitations in their new clerical roles. And both found their social worlds transformed, from the open, fluid networks of traditional elite life into the doctrinal camps, jurisdictional paths, and intricate rivalries of church leadership.