Michael Edward Moore’s A Sacred Kingdom: Bishops and the Rise of Frankish Kingship, 300-850 is a detailed, deeply researched study of the formation of the political theology of the Frankish Kingdom from the collapse of Rome through the fragmentation of the Carolingian dynasty. Moore traces the Christianization of the ideal of kingship, emphasizing the role of bishops and their use of episcopal councils to formulate and disseminate a vision of Christian society and of kingship.

In contrast to some recent work on this period, Moore emphasizes the religious dimensions of the bishops’ work. It was precisely as liturgical and ritual specialists that they exercised their most important political functions.

Through liturgy, their influence spread to all the major concerns of the citizenry - birth, death, marriage. The bishops stood on the threshold between heaven and earth, between this world and a world charged with sanctity, and they were marked off as a separated body within the body by their tonsure (in contrast to the long-haired kings) and their distinctive dress. As sacred persons, they strove to occupy the center of Frankish society, with considerable success over several centuries. Priests were crowned, sacred kings.

Kings, conversely, were anointed “priests,” and Moore argues that their sacral character was specifically Christian rather than a pagan leftover. At the heart of the episcopal social vision was the belief that the kingdom was the people of God, the body of Christ, ruled by the twin authority of king and bishop. They gave the Frankish kingdom a divine purpose, styling the Frankish kings as missionary kings whose aim was to subdue and convert surrounding kingdoms. Because of the bishops, a warrior kingdom with warrior values was given a “sublime value” and “a divine mission” (371).

Moore is even-handed throughout, and gives attention to the workings of councils, the liturgical shape of episcopal power, the various patristic sources on which Frankish bishops drew, and their development of a distinctive political vision. It is a rewarding entree into one of the formative periods of Western political theology.