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The Two Powers

Covering decades that included the last major crusades, the birth of the Inquisition, and the unexpected invasion of the Mongols, The Two Powers shows how Popes Gregory and Innocent's battles with Emperor Frederick shaped the political circumstances of the thirteenth-century papacy and its role in the public life of medieval Christendom.

The Two Powers
The Papacy, the Empire, and the Struggle for Sovereignty in the Thirteenth Century

Brett Edward Whalen

2019 | 328 pages | Cloth $85.00
American History / Religion
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Table of Contents

Prelude. The Legate

Chapter 1. A Contested Vow
Chapter 2. Reforming the Peace
Chapter 3. The Widening Gyre
Chapter 4. Christendom in Crisis

Interlude. The Vacancy

Chapter 5. A New Hope
Chapter 6. The Council
Chapter 7. Christendom at War
Chapter 8. The Price of Victory

Postlude. The Afterworld

List of Abbreviations

Excerpt [uncorrected, not for citation]


Entering the chapel of Saint Sylvester in the basilica of Santi Quattro Coronati in Rome, one encounters a sequence of frescoes from the year 1246 that speaks to the dual nature of Christian sovereignty in the Middle Ages. The images present a meeting over nine hundred years earlier between Pope Sylvester, the bishop of Rome, and Constantine, the Roman emperor. Although this encounter never actually happened, medieval Europeans generally believed that that it did. The paintings commence with scenes of the pagan ruler's leprosy and refusal to bathe in the blood of slaughtered infants, a cure recommended to him by pagan priests, followed by his vision of the apostles Peter and Paul. The two saints instruct him to seek out Sylvester, who was hiding on the outskirts of Rome due to the imperial persecution of the Christian church at the time. The pope meets and baptizes the stricken ruler, healing him of his affliction. Out of gratitude, the emperor hands over his tiara to Sylvester, denoting his surrender of the Western empire to the Roman pontiff. A concluding scene shows Sylvester on horseback while Constantine humbly acts as his groom. By visualizing the past in this manner, the frescoes communicate a message about the proper relationship between the "two powers," that is, between the spiritual authority of priests and the temporal might of secular rulers, embodied above all by popes and emperors. As the example of Constantine and Sylvester revealed, emperors should ultimately defer to popes, recognizing their superior form of sacerdotal sovereignty.

Outside the walls of the chapel, when its frescoes were new, Christians faced a far more turbulent relationship between the chief representatives of the two powers: a violent division between Pope Innocent IV and the Hohenstaufen emperor, Frederick II. Contention between the papacy and the imperial ruler had begun under Innocent's predecessor, Gregory IX, who excommunicated Frederick not once, but twice: for the first time in 1227, when the emperor failed to depart on crusade by an agreed-upon deadline, and again in 1239 (nine years after their previous reconciliation), when he was accused of various sins, crimes, and abuses of the church. The two had remained fiercely at odds when Gregory died in 1241. After his election one and a half years later, Innocent seemed poised to make peace with Frederick until negotiations between them collapsed and he fled to the city of Lyons. In July 1245, at the Council of Lyons, the pope deposed the Hohenstaufen ruler from his kingdoms and honors, a judgment rejected by the emperor as an illegal act of papal overreach into temporal affairs. Intensifying conflict between the two sides followed for years to come. In 1250, unrepentant and excommunicate, Frederick died while still warring with the pope. Returning to Italy, Innocent spent the remainder of his life fighting with Frederick's heirs, until his own demise at Naples four years later.

Reading many of Frederick II's modern biographers, one gets the unmistakable impression that Gregory and Innocent in turn shared a deep-seated desire to destroy the emperor, viewing him as the principal danger to the papacy's territorial possessions on the Italian peninsula and their main competitor for universal sovereignty over Christendom. Although such histories of the Hohenstaufen ruler are in many cases decades old, they continue to cast a long shadow over Gregory and Innocent, in part due to the lack of recent book-length studies on the two popes. Perhaps not surprisingly, Frederick emerges as the clear protagonist in such works. While the emperor has enjoyed the reputation of being an iconoclast and a modern man born before his time, his papal opponents seem eminently "medieval" by comparison, that is to say, intolerant, narrow-minded, and determined to realize their theocratic aspirations at any cost. Desperate to eradicate Frederick, Gregory and Innocent squandered the church's wealth, discredited the crusades by turning them against their foe, and damaged their office's moral standing, setting the papacy on the slow road to decline and near ruin in the later Middle Ages.

In this book, I retell and reevaluate the history of Gregory IX and Innocent IV's combative relationship with Frederick II from a different perspective: that of the medieval public realm. To influence, restrain, and combat the reigning Christian emperor, the two popes had to convince the wider public about the legitimacy of their cause, including not only kings, archbishops, and other highly placed elites but also members of the lesser clergy and lay nobility, crusaders and mendicants, merchants and burgers, and parish priests and their parishioners, among others. The papal confrontations with the Hohenstaufen ruler took place not just on the level of high politics and diplomacy but also in city streets, ports, plazas, and other open spaces. The battles between the popes and the prince could be heard in the proclamation of excommunications, the preaching of sermons, or the contrary silences imposed by interdict. Chroniclers with their own stakes in the outcome memorialized the clash between the papacy and empire in their historical writings, leaving traces of wider reactions to the turmoil disrupting their society: the circulation of wild rumors, the clamoring of the people, and the awe caused by apocalyptic signs of a world in crisis. Nothing less than the fate of Christendom seemed to hang in the balance between the discordant two powers.

The point of this study is not to turn the tables on Frederick, making Gregory and Innocent into heroes of the story, the emperor into the villain. Scholars with confessional sympathies have tried this before with equally skewed results. In the pages below, however, I devote the majority of my attention to the means of communication, documentary culture, performances, and media that turned the papacy's spiritual and sacramental authority into consequential forms of social and political action. While highlighting the papal side of the epoch-making struggles between the two powers, I also keep a close eye on Gregory and Innocent's other shared commitments, including their widely publicized mandates to create peace in Christendom, to promote crusading, and to eradicate heresy from the church. Those projects for the common good of Christendom, as the two popes presented them, shaped their response to Frederick's imperial reign, not the other way around. Ironically, perhaps, given the assumption of irreconcilable differences between him and the two popes, Frederick shared many of those same goals, albeit with his own ideas about how to realize them. In many ways, the popes and the prince disagreed so publicly and so violently because they agreed on so much.

By taking such an approach to the subject, this book seeks to restore a sense of contingency to the history of the thirteenth-century struggles between the papacy and empire, rather than viewing them as a more or less inexorable outcome of opposing political ideologies. Theoretically supreme in the theological and juridical realms, the bishops of Rome faced constant and unexpected challenges, constraints, and limitations to the enactment of their priestly sovereignty in the public realm. No one must have understood this better than Gregory and Innocent. Their contentious relationship with Frederick forced them to intervene in European politics and society in far-reaching and controversial ways, publicizing his excommunicate and eventually deposed status, attacking his reputation through propagandistic letters, deploying papal legates to act against his interests, declaring crusades against him, and transferring vast sums of ecclesiastical wealth to support the papacy's allies against Frederick's supporters. The results of those efforts remained imperfect and reliant upon forces that the popes could not easily or always control. Innocent, after all, was not on hand to see the frescoes of Sylvester and the deferential Constantine unveiled in Santi Quattro Coronati. He remained in exile at Lyons, unable to return to Italy for as long as Frederick lived and his allies dominated the road to Rome.


To a considerable extent, the history of Gregory IX and Innocent IV's battles with Frederick II remains inextricably bound to the larger question of the medieval "papal monarchy." The term papal monarchy is a compelling and evocative one, but in some ways misleading—even in the Middle Ages, popes did not rule like kings over the faithful. In its technical, juridical sense, the concept of the papal monarchy denotes the pope's "fullness of power" (plenitudo potestatis) over the church and its offices, his position atop the ecclesiastical hierarchy and status as the final arbiter of canon law, able to grant dispensations, definitively settle disputes, and decide legal cases. Used in a more capacious formulation, accurately or not, the papal monarchy suggests the awesome ambitions of the medieval papacy to stand as the supreme sovereign of Christendom, asserting the ultimate superiority of the priesthood (sacerdotium) over temporal rulership (regnum). Starting with papal reform movement of the eleventh century, building momentum in the twelfth century, and peaking in the thirteenth, the papal monarchy instantiated the ambitions of popes, theologians, and canon lawyers to realize the papacy's juridical authority over worldly princes of all kinds, thereby creating what has memorably been described as a hierocratic vision of the Christian political order.

As will become evident through this book, theologically inflected legal concepts of sovereignty did indeed play a crucial role in the elaboration of papal claims to wield not just spiritual but also, in exceptional cases, temporal power over secular monarchs. But we need to look beyond the law in a narrow sense to discern the public contours of the thirteenth-century struggles between the papacy and empire. Needless to say, the vast majority of contemporary Christians were not canon lawyers and did not understand the technicalities of the canonistic tradition. They nevertheless possessed varying degrees of awareness about the papacy's jurisdiction over their lives, the pope's status as the Vicar of Christ, his fullness of power over the church, his "power of the keys" over sin, and his possession of the "spiritual sword." These terms, at once sacramental and juridical, frequently feature in non-canonistic sources. In this regard, the dilemma of the two powers played out in what Daniel Lord Smail has called the "legal culture of publicity" in the Middle Ages. Powerful popes and rulers might seem far removed from the ordinary men and women that Smail describes in medieval Marseilles, who needed "to perform openly and in the public eye in order to inscribe facts in the memories and gossip networks that comprised the archive on which proof in subsequent legal quarrels might depend." And yet, members of the papal curia and imperial court likewise argued about the law in the "public eye," sacrificing legalistic precision for sensationalism and seeking to create "public archives of knowledge" on a Christendom-wide scale.

Certainly, one must be cautious when translating the medieval Latin word for "public" and its variants (publicus, publice, publicare), terms that commonly designated something as "lordly," "royal," or "official" or meant "to reserve as a royal prerogative" or "to confiscate for the fisc." In our thirteenth-century sources, however, the word "public" suggested and designated many other things that come far closer to what we might now associate with public life. Canon law distinguished between the "internal forum" of the conscience and the "external forum" that encompassed "public or manifest transgressions of the Church's law or divine law." Public acts included the presentation and reading of documents "in public" (in publico) before witnesses and crowds, deeds done "publicly" (palam) as opposed to "secretly" (clam), and the bringing of news "to public notice" (ad publicam notitiam). The invocation of the public takes shape in descriptions of information spreading "among all the people" (in universis populis), "throughout the entire world" (per totum orbem) or "throughout all the lands of Christendom" (per terras totius Christianitatis), not only in written form but also as rumors and word-of-mouth news—much of it, what we might now call "fake news." Publicly embodying papal and imperial authority, apostolic legates and their imperial counterparts conveyed all sorts of communications to wider constituencies: "solemn," "public," and "open" letters or, by contrast, "closed" and "secret" ones, along with "letters of credence," "excusatory letters," and "exhortatory," "admonitory," and "testimonial" letters among them. Rituals of anathema and the denunciation of sinners took place publicly, as did the convocation of citizens in communal spaces or the summons for Christians to assemble at church councils. One even finds a sense of "public scandal" (scandalum publicum), the outrage caused by shameful behavior and the reputations ruined by scurrilous gossip.

Through routes that are sometimes but not always traceable, letters, documents, and orally transmitted information (or disinformation) made their way to monastic and civic chroniclers, who emplotted what they read and heard into narratives of their own design. The word "chronicler" conjures images of medieval scribes, removed from the events of the world they described, often with a confused sense of chronology or just a poor grasp on the facts. Yet the chroniclers that we will encounter in this book, and not just the ones that scholars label Guelf (more or less pro-papal) and Ghibelline (favoring the empire) possessed their own stakes in the battles between the popes and the Hohenstaufen prince: figures like the English monk Matthew Paris, outraged at the financial costs of the papacy's struggle with Frederick; or Salimbene of Adam, the well-traveled Franciscan friar, forced to traverse the war-torn landscapes of northern Italy during the years of conflict between papal and imperial allies. Such history-writers did more than passively record events: they memorialized a certain version of the past from their presentist perspective. They preserved—to some extent, imagined—conversations, rumors and gossip, gestures, and rituals they judged worthy of remembrance. In this regard, we can treat their mistakes, biases, and lack of factual accuracy as enriching their historical value rather than disqualifying them as unreliable primary sources, a metric of sorts for contemporary reactions to the astonishing and sensational events of the thirteenth century.

At its most ambitious, this book suggests that we need to rethink the public nature of Christendom in the Middle Ages. Among many other implications, this reconceptualizing of medieval Europe's Christian society has particular implications for the study of papal sovereignty. Historians have long emphasized the Roman papacy's contributions to the unity of Latin or Western Christian believers, who were bound together by their shared sacred language, rites, laws, and obedience to Rome as the "mother and head of all churches." Popes helped to shape that common identity through compelling ideas, stressing the unique role of their office as the unifier of the faithful on earth, and also through increasingly sophisticated forms of governance and communication, including the college of cardinals and consistory; the chancery and archives; a systematic tradition of canon law; and the staging of ecclesiastical councils, to name a few key examples. As an institution, the papacy acted as a leader in the broader information revolution that began to transform Europe starting in the eleventh century, with its well-known shift "from memory to written record." By the thirteenth century, such changes in government, communication habits, and record keeping continued to accelerate. More effectively than before, the Roman curia functioned as the final court of appeals for ecclesiastical disputes; a source of privileges, immunities, and exemptions; a provider of benefices and dispensations; and a center for fundraising through taxes and subsidies, bringing petitioners and favor seekers to Rome (or wherever else the pope happened to be), while legates, envoys, and judge-delegates empowered by the Apostolic See conveyed papal letters, rescripts, and other documents into every corner of Europe and beyond.

Some might nevertheless question the premise that Christendom formed a "public" or "open" realm. As a "feudal" society, it has been argued, medieval Europe did not possess a genuine public sphere, lacking as it did the requisite economic conditions, spaces of interaction, and forms of communication—namely, print—for an informed citizenry engaging in discourse about the public good. Others have presented Christendom as a monolithic "religiously imagined community," its inhabitants lacking a self-consciousness of their own historicity. In recent years, however, scholars have pushed back against dismissive views of medieval and early modern publics, demonstrating that premodern societies possessed their own performative cultures and communicative practices, their own open forums for debate over the social and political conditions of their lives. Still others have stressed the public as a "powerful rhetorical and discursive concept" rather than an actual space or lived interaction of citizens, conceptualizing the public within a nexus of texts, forming part of a social imaginary, a "fiction, which, because it can appear real, exerts real political force." This sort of discursive public need not be limited by putatively modern technologies, spaces, and social categories.

Viewed from this perspective, rather than as a hierarchical, feudal, or static society lacking public awareness, medieval Christendom formed a dynamic place of circulating people, texts, rumors, and shared performances. As the principal dilemma of Christian sovereignty in the Middle Ages, the relationship between the two powers took shape within that open realm and in turn helped to shape it. Although far from the first conflict between popes and emperors, Gregory and Innocent's successive struggles with Frederick II marked an especially vital and intensive episode of public crisis over the proper ordering of Christendom, one with the potential for violence that spilled into the open on more than one occasion. Even so, rather than eagerly seeking combat to the death, the two popes and the emperor more often seemed to be searching for ways to defer, delay, or defuse their political confrontations, while other parties sought advantage in the turmoil caused by the division between the popes and the emperor. That history of reluctance, compromise, and occasional cooperation between the two sides forms an equally crucial, albeit largely forgotten, part of their relationship.


The chapters below are organized chronologically and divided into two parts. After a prelude describing Hugolino dei Conti's legation to Lombardy in 1221, before he became Gregory IX, Part I starts with the pope's election in 1227 and ends with his death in 1241. Chapter 1 examines Gregory's conflict with Frederick over the emperor's contested crusade vow, a conflict that lasted until their reconciliation in 1230; Chapter 2, the years from 1230 to 1235, an often overlooked period of dialog and cooperation between the two powers, including their alignment of interests over the crusades and the fight against heresy; Chapter 3, the pope and emperor's increasingly unrestrained arguments over Frederick's political actions in Lombardy and perceived abuse of ecclesiastical liberties; and Chapter 4, Gregory's second excommunication of Frederick and their ensuing battles until the pope's demise. An interlude between the two parts examines the intervening vacancy in the apostolic office.

Part II covers the period of Innocent IV's papacy. Chapter 5 explores the first year and half after his election, when the new pope pursued an unsuccessful peace with Frederick; Chapter 6, the Council of Lyons in 1245, where Innocent issued his formal judgment deposing the emperor; Chapter 7, the following years of unrestrained warfare between papal and imperial supporters until Frederick's death in 1250; and, Chapter 8, Innocent's fight with the deceased emperor's heirs until his own demise in 1254. A brief postlude follows, describing contemporary reactions to the pope's death and the immediate fallout from his battles with the Hohenstaufen dynasty.

The epilogue to this book speculates about the long-term significance attributed to the battles between sacerdotium and regnum. After all, medieval clashes between popes and monarchs feature in some of the most cherished narratives of modernity. Theorizing about the two powers, many argue, first suggested the possibility that human activity could be divided into autonomous spheres, one sacred, the other secular. Others assert that fighting between popes and worldly rulers formed an unintentional buttress against theocratic rule, assuring that neither party could realize their aspirations to complete dominion over Christian society and thereby creating space for the eventual retreat of religion from the public sphere. Between the "hammer and anvil" of such conflicts, as Francis Oakley recently put it, "political freedoms in the West were eventually to be forged." There are sound reasons for locating such contributions to the western political tradition in the Middle Ages. Yet, in this present era of resurgent "public religions," I have come to wonder whether we should so confidently emplot the history of two powers into a narrative of progress from the medieval past, characterized by the imbrication of religion and politics, to the modern present that supposedly distinguishes between them.

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