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.17 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.18 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, using them as 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.19 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.”20 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 fund-raising 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.21
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.22 Others have presented Christendom as a monolithic “religiously imagined community,” its inhabitants lacking a self-consciousness of their own historicity.23 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.24 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.”25 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.26 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