Brings to the contemporary reader the major documents of the prolonged debate, revealing the ideas behind the conflict and relating them to the practical politics of the medieval world. Among the items recorded here are Henry IV's defiance of the papacy over the issue of lay investiture, the rise of the papacy to political power under "lawyer-pope" Innocent III, and Philip IV's humiliation of Boniface VIII. The author interprets these disputes and provides a clear narrative of church-state relations in the Middle Ages, explaining the issues that loomed so large before the men of the time.

From the Introduction: We need not be surprised, then, that in the Middle Ages also there were rulers who aspired to supreme political and temporal power. The truly exceptional thing is that in medieval times there were always at least two claimants to the role, each commanding a formidable apparatus of government, and that for century after century neither was able to dominate the other completely, so that the duality persisted, was eventually rationalized in works of political theory and ultimately built into the structure of European society. This situation profoundly influenced the development of Western constitutionalism.

To understand the growth of Western constitutional thought, we need to consider both ecclesiology and political theory, ideas about the Church as well as ideas about the state. In this book Professor Tierney traces the interplay between ecclesiastical and secular theories of government from the twelfth century to the seventeenth. He shows how ideas revived from the ancient past - Roman law, Aristotelian political philosophy, teachings of Church fathers - interacted with the realities of medieval society to produce distinctively new doctrines of constitutional government in Church and state. The study moves from the Roman and canon lawyers of the twelfth century to various thirteenth-century theories of consent; later sections consider fifteenth-century conciliarism and aspects of seventeenth-century constitutional thought. Fresh approaches are suggested to the work of several figures of central importance in the history of Western political theory. Among the authors considered are Thomas Aquinas, Marsilius of Padua, Jean Gerson, Nicholas of Cues and Althusius, along with many lesser-known authors who contributed significantly to the growth of the Western constitutional tradition.

Medieval civilization came of age in thunderous events like the Norman Conquest and the First Crusade. Power fell into the hands of men who imposed coercive new lordships in quest of nobility. Rethinking a familiar history, Thomas Bisson explores the circumstances that impelled knights, emperors, nobles, and churchmen to infuse lordship with social purpose. Bisson traces the origins of European government to a crisis of lordship and its resolution. King John of England was only the latest and most conspicuous in a gallery of bad lords who dominated the populace instead of ruling it. Yet, it was not so much the oppressed people as their tormentors who were in crisis. The Crisis of the Twelfth Century suggests what these violent people—and the outcries they provoked—contributed to the making of governments in kingdoms, principalities, and towns.