Historians commonly designate the High Middle Ages as the era of the "papal monarchy," when the popes of Rome vied with secular rulers for spiritual and temporal supremacy. Indeed, in many ways the story of the papal monarchy encapsulates that of medieval Europe as often remembered: a time before the modern age, when religious authorities openly clashed with emperors, kings, and princes for political mastery of their world, claiming sovereignty over Christendom, the universal community of Christian kingdoms, churches, and peoples. At no point was this conflict more widespread and dramatic than during the papacies of Gregory IX (1227-1241) and Innocent IV (1243-1254). Their struggles with the Hohenstaufen Emperor Frederick II (1212-1250) echoed in the corridors of power and the court of public opinion, ranging from the battlefields of Italy to the streets of Jerusalem. In The Two Powers, Brett Edward Whalen has written a new history of this combative relationship between the thirteenth-century papacy and empire. Countering the dominant trend of modern historiography, which focuses on Frederick instead of the popes, he redirects our attention to the papal side of the historical equation. By doing so, Whalen highlights the ways in which Gregory and Innocent acted politically and publicly, realizing their priestly sovereignty through the networks of communication, performance, and documentary culture that lay at the unique disposal of the Apostolic See. Covering pivotal decades that included the last major crusades, the birth of the Inquisition, and the unexpected invasion of the Mongols, The Two Powers shows how Gregory and Innocent's battles with Frederick shaped the historical destiny of the thirteenth-century papacy and its role in the public realm of medieval Christendom.

Reprint of the original, first published in 1860.

On the Pope (Du Pape) is the main political-philosophical work of the counter-revolutionary writer and philosopher, Joseph de Maistre. Maistre worked for 20 years on the writing of his magnum opus, a book that laid the foundation for his invention of political ultramontanism. Ultramontanism was a school of thought of the Catholic Church that promoted the doctrine of central papal supremacy in matters of governance and spirituality. Championed by Pope Pius IX, the ultramontanists attained their greatest triumph in the late 19th century with the formal proclamation of papal primacy and infallibility. On the Pope is divided into four parts. In the first part, Maistre makes the argument for his thesis that there is "no pope without the supremacy which belongs to him" and "no Catholicism without one pope." His argument in favor of papal infallibility stands out in the history of theology because he was among the earliest Catholic writers to openly discuss the doctrine. Part two reveals the key components of Maistre's political thought: His absolutist ideas about the nature of sovereignty, his unique argument for the divine origins of all forms of political sovereignty, and his rejection of social contract theories on the origin of society and sovereignty. Part three is devoted to demonstrating Maistre's argument that, above all, nations need a higher sovereign to help protect against the abuses of power, and that this sovereign should be the pope, as the savior and creator of European civilization. He argues that the only nations that have known civil liberty are those which "have remained sufficiently under the influence of the Sovereign Pontiff." Part four deals primarily with "schismatic churches." Maistre felt that the schismatic churches would inevitably fall into Protestantism, and from Protestantism through Socinianism into philosophic indifference. For "no religion can resist science, except one."

Sovereignty has always been an important concept in political thought, and at no time in European history was it more important than during the perplexed conditions of the thirteenth and fourteenth centuries. Universal government was a fading dream, giving way to the new conception of the national state and the whole basis of political thought was being reorientated by the influx of Aristotelian ideas. Dr Wilks's book is an attempt to clarify the more important problems in the political outlook of the period. He shows that at this time the theologians and literary writers, especially Augustinus Triumphus of Ancona, had built up a complete theory of sovereignty in favour of the papal monarchy, based on a neo-Platonic, Augustinian view of the church as a universal and totalitarian state.

[God’s Diplomats is] a mix of impartial description and informed opinion. Not everyone will agree with how different issues are framed, or how different figures are portrayed. But what certainly cannot be argued with is the fact that Gaetan has given a gift not only to foreign policy practitioners, but also to American Catholics. You will not find a book on Church diplomacy as accessible, comprehensive, and faithful, as God’s Diplomats. It is a must read for anyone interested in understanding the Vatican’s diplomatic priorities better — and especially why they don’t always align with America’s. ― National Catholic Register Using inside sources and extensive field reporting about the secretive, high-stakes world of international diplomacy, Vatican reporter Victor Gaetan takes readers to the Holy See to explicate Pope Francis's diplomacy, show why it works, and to offer readers a startling contrast to the dangerous inadequacies of recent U.S. international decisions.