Reviewed by: The Formation of Christian Europe: The Carolingians, Baptism, and the Imperium Christianum by Owen M. Phelan Matthew Bryan Glllis The Formation of Christian Europe: The Carolingians, Baptism, and the Imperium Christianum. By Owen M. Phelan. (New York: Oxford University Press. 2014. Pp. ix, 312. $ 105.00. ISBN 978-0-19-871803-1.) This is a welcome book. The author argues how reformers under Charlemagne used baptism, understood as sacramentum, as the fundamental organizing principle for Carolingian imperial society—a development that would shape the European world throughout the medieval period and beyond. One of the great strengths of this book is how it combines the study of intellectual history, ritual theory and practice, the framing and legitimizing of political power, and the development of a particular religious identity within an imperial framework. Chapter 1 offers a genealogy of sacramentum as an ordering concept from Antiquity to the early Middle Ages. Key here was the overlap between legal and theological meanings. Indeed, sacramentums Roman origins as a military oath of allegiance later proved remarkably useful to Carolingian reformers keen to link expectations of loyalty to the imperial regime with the spiritual transformation of baptism. The next three chapters provide a sustained analysis of sources from Charlemagne’s reign, when intellectuals worked to transform baptism conceptually and ritualistically into a program for imperial Christian identity formation. Chapter 2 examines how sacramenta, especially baptism, gave Carolingian leaders ways of framing their political authority in religious terms in order to envision the imperium christianum as a polity. The chapter largely explores Frankish interactions with “others,” such as Spanish heretics in the Adoptionist Controversy, Saxon pagans who repeatedly rejected their coerced baptisms and Frankish political domination, and Jews who were expected to take non-baptismal pledges of loyalty in order to enjoy protections and privileges within the empire. Chapter 3 focuses on the intellectual Alcuin’s efforts to develop a program for producing Christian imperial subjects. Here Phelan investigates Alcuin’s missionary theories, his concerns for moral education, his influential interpretation of the rite of baptism (the Primo paganus), and his circle of important allies and correspondents who embraced his baptismal program. Chapter 4 analyzes the Carolingian machinery of Christian identity formation at work through a series of sources from Charlemagne’s last years, in particular his encyclical letter on baptism (811/812) and the numerous episcopal documents created in response to that questionnaire. Central to the author’s argument is that Alcuin’s approaches to baptism provided the basis for theological unity in these later discussions, while still allowing for ritual and liturgical diversity. Chapter 5 examines how ninth-century authors—in particular Bishop Jonas of Orléans and Dhuoda of Septimania—adapted Carolingian conceptions of baptism for lay readers. Since infant baptism predominated, godparenting, confirmation, and the sacrament of penance became crucial to maintaining baptismal promises, thereby serving to shape Frankish Christian identity formation after imperial expansion ended. Phelan’s choice of ninth-century authors and texts is strategic and necessary due to the tremendous increase in theological writings after Charlemagne. The conclusion turns to Notker the Stammerer’s Gesta Karoli in order to [End Page 110] illumine how this particular late ninth-century author criticized Charlemagne’s descendants for failing to understand baptism’s theological and ritualistic power to expand the imperium christianum. Phelan’s findings are convincing. It is refreshing to see Frankish Christianity linked so unreservedly to Carolingian imperial ambitions. Future studies of other sources, including ninth-century biblical commentaries and handbooks for priests, may complicate the author’s view of the creation of imperial Christian subjects not only from the standpoint of theologians and bishops, but also of common priests active in pastoral care. Overall, this thoughtful study persuasively casts the Carolingian Empire as a fundamentally religious enterprise in the medieval exercise of power. Matthew Bryan Glllis University of Tennessee, Knoxville Copyright © 2017 The Catholic University of America Press