Introduced and translated by Arthur Monahan, this work is a specific attempt to redress the historical imbalance of material available in English dealing with the classic medieval conflict in church/state relations.

Written at the turn of the 14th century, Giles of Rome's De ecclesiastica potestate is a papal tract written at the height of Pope Boniface VIII's conflict with King Philip IV of France.

How was medieval Europe held together? People of dissimilar occupations and economic interests, living in widely separate parts of western Europe, came to recognise and act upon a common set of cultural beliefs. This framework of shared social customs and values, that is distinctively medieval and European, arose from the interaction between secular and ecclesiastical power, but these developments can no longer be convincingly viewed as arising solely from events such as the Wars of Investiture and the Fourth Lateran Council. The historiography of this study shows that the medieval mental framework was not solely concerned with the great struggles between Rome and lay rulers, but neither can we assume that local communities were islands of cohesion in a wider world of chaos and conflict. The case studies presented demonstrate how texts were used as weapons by ecclesiastical authorities in defining their relationships with lay powers. Other studies here focus upon how land and kinship was used to define the social relations between the laity and the clergy.The concluding section concentrates upon the solution of conflicts.

During the fourth century a.d., theological controversy divided Christian communities throughout the Eastern half of the Roman Empire. At stake was not only the truth about God but also the authority of church leaders, whose legitimacy depended on their claims to represent that truth. In this book, Carlos R. Galvao-Sobrinho argues that out of these disputes was born a new style of church leadership, one in which the power of the episcopal office was greatly increased. He shows how these disputes compelled church leaders repeatedly to assert their orthodoxy and legitimacy—tasks that required them to mobilize their congregations and engage in action that continuously projected their power in the public arena. These developments were largely the work of prelates of the first half of the fourth century, but the style of command they inaugurated became the basis for a dynamic model of ecclesiastical leadership found throughout late antiquity.

'I study power' – so Robert Louis Benson described his work as a scholar of medieval history. This volume unites papers by a number of his students dealing with matters central to Benson's historical interests – ecclesiastical institutions and administration, emperorship and papacy, canon law, political ideology, and historiography. The justification and exercise of political power is considered in two chapters that look at how the hagiography of a late Roman military saint, Maurice, was harnessed in the 11th century to the discussion of the power exercised by both emperor and pope, and how both pious purpose and political pretext animated the Hohenstaufen emperors' suppression of heresy. Three subsequent chapters focus on the Church: a study of the legal commentaries that taught that the 'authority to bind and loose' in a specific ecclesiastical matter could be determined by the opinions of 'the elders of the province'; an argument that Innocent III's administration of the Roman church represented a model for the ordering of all Christian society; and an inquiry into the doctrinal formation of the 'territorial principle' in the exercise of jurisdiction by papal legates. The late Middle Ages provides the focus for two additional studies, namely an exploration of the issues of power and authority in the charitable institutions of Cologne in the 13th–14th centuries, and the argument that the current desire for universal standards of governmental conduct in the area of basic human rights hearkens back to natural law theory as outlined in the 15th century by Nicholas of Cusa. Two historiographical studies round out the volume: an estimation of modern research regarding the political theology of late antiquity, and a reflection on Benson's own contribution to historical scholarship. Together, these papers both epitomize and further develop Benson's distinctive approach to the study of the Middle Ages, while themselves making their own important contribution.