This chapter argues that in the early medieval period, Catholic law both reflected and reinforced a largely “horizontal” Church structure, in which bishops played a central role, often in close engagement with secular lords and rulers. The first part of the chapter surveys the types of existing evidence for early medieval Church law, from the Carolingians up until the Gregorian Reform of circa 1050. The second part focuses on continuities between the Carolingian reforms and the tenth and early eleventh centuries. Recent scholarship has increasingly argued that the Carolingian reforms did not end with the fragmentation of the Carolingian empire. Building on that work, this chapter describes three examples of continuities between the Carolingian and Ottonian periods.

The tenth and early eleventh centuries often fall between the cracks of the “Carolingian Renaissance” and the “Gregorian Reform” of the eleventh-century papal reform movements. Yet scholars are now paying closer attention to the “long tenth century,” c. 900–1020/50. This new research has undermined the idea that Church law sank into a dark period. Canon law, in fact, may be more difficult to describe in this time than in later periods, precisely because it took place on a “horizontal” level, with many local users, rather than unified under a “vertical” papal monarch, as it would be later. Church law was pluralistic in many senses. Many people used it: the local priest; abbots and monks; the bishop, both in teaching and in administering episcopal courts; and councils, sometimes with popes and emperors present. The remarkable number of canon law manuscripts from this period attests to the considerable local interest in canon law. Collections of Church law from this period also continued to be copied into the high Middle Ages – which also testifies to the significance of the achievements of this period. Viewed diachronically, Church law in this period built upon Carolingian legislation as well as institutions and structures.

The Decretum of Burchard of Worms (d. 1025) was a popular and much copied canonical collection. Burchard drew on existing collections, which provided him with a mass of items that included conciliar decrees, patristic extracts, penitential prescriptions, and papal letters. He organized these into a coherent, relatively concise handbook designed for bishops to use in visitations and in their daily administrative lives. But he also intended his book to be used as a resource for teaching, as he explains in the preface. Coherence, clarity, and organization are the collection’s hallmarks. Whereas his predecessor, Regino, assumed that the reader would be able to derive an answer from multiple, sometimes conflicting texts, Burchard edited and assembled the texts to provide consistent, straightforward answers to a reader’s questions. The Decretum covers a wide range of topics that a bishop might need to address, including ritual, lay offenses, excommunication, penance, and even eschatology. Like Regino, Burchard sometimes forged new material, but for the most part he preferred to alter existing texts to make them consistent and to enhance their authority.

The Libri duo by Regino of Prüm (d. 915) was a handbook for bishops and other clerics to use in pastoral work and in teaching. The Libri duo gives detailed instructions for episcopal visitations, when a bishop would visit the parishes of his diocese, adjudicating offenses committed there. The collection includes penitential material as well as canon law, but these modern categories do not map neatly onto the lived experiences of Carolingian bishops. The Libri duo not only addresses the correction of offenses but also provides instructions for ritual practice and church administration. Regino may have manufactured or “forged” some of his canons, since they appear here for the first time. But, as Wilfried Hartmann has suggested, he may have drawn upon less familiar canonical sources, such as episcopal capitularies; or, as Sarah Hamilton has proposed, he may have been describing contemporaneous practices. Although the collection enjoyed only limited circulation, Burchard of Worms used it as a source of material and as a model for his popular Decretum.