Gregory’s plans for the crusade would take some unexpected directions and eventually become a source of renewed tension between him and Frederick. In 1234, however, those problems lay in the future. During its earliest stages, the call for the Baron’s Crusade illustrated the compelling public profile of the Roman pope as the spiritual leader of the universal church and evangelizer of peace working in concert with secular powers to achieve the common good of defending the Holy Land, where Christ had redeemed humanity. Mediating in October of that year between Frederick and the Lombards, who were still at odds over their past grievances and the extent of the emperor’s rights, Gregory reminded them once again of the need for unity among Christians as a precursor to a successful crusade, especially at a time when the pope, moved to action by the “many clamors” reaching him from the Holy Land, sought to bring them expeditious aid. With Christendom at peace, Gregory envisioned, holy war would be exported beyond its borders.61
A Hidden Threat
As Pope Gregory publicized his plans for the upcoming crusade, he identified another threat to the peace in Christendom, a grave menace within the faithful: heresy. Heretics, the pope insisted, teaching their foul doctrines “secretly” and operating in the “shadows,” tricked the simpleminded into questioning bedrock elements of their faith, such as the incarnation of Christ, the efficacy of the sacraments, and the resurrection of the body at the Final Judgment. They also tried to cast doubt on the pope’s “fullness of power” over the church, his power of the keys over sin, and his right to excommunicate and interdict Christians. Eradicating heresy by wielding the spiritual sword against heretics represented one of Gregory’s chief responsibilities as the bishop of Rome and leader of the universal church. Facing this duty, the pope needed a partner to wield the material sword, one who would coerce and, if necessary, execute those judged guilty of heresy: namely, the Christian emperor, among other representatives of the secular arm.
Much like the crusade to recover the holy places, during the years after the Treaty of San Germano the battle against heresy formed a point of convergence for the two powers, allowing the pope and emperor to stress their shared duty to root out and destroy that hidden threat. As observed earlier in this book, the papal effort to combat heresy did not start with Gregory, but his time as pope marked an important—for some, infamous—moment in the history of the medieval church: its “inquisitorial turn,” the intensifying, centralizing, and institutionalizing of anti-heretical measures. In the popular imagination, the Inquisition summons images of dark dungeons, of clergy torturing more-often-than-not innocent victims far from prying eyes. To the contrary, the hunt for heretics in the thirteenth century involved the pope and his representatives in public displays of priestly authority, including acts such as preaching sermons, performing rites of excommunications, reading letters aloud and exhibiting their seals, receiving testimony in civic spaces, and publicizing anti-heretical statutes, among other “technologies” openly deployed against the hidden threat of heresy.62
For Gregory, acting as the bishop of Rome and lord of the Papal States, fighting heresy was in part a local duty that might have reminded him of his time as a cardinal legate in Lombardy years earlier. According to the pope’s biographer, after returning to Rome in 1230 following his reconciliation with Frederick at San Germano, Gregory discovered that “Patarene” heretics had spread like a “contagion” throughout the city during his absence, seeking to cause “public harm” through “hidden means.” After conducting an inquiry into the matter, in February 1231 the pope convoked a meeting of the Roman senate and people before the Church of Santa Maria Maggiore, where he condemned a great number of clergy and lay people, both men and women among the latter, based on the testimony of witnesses or their own confessions. The clergy suffered deposition, their sacred vestments removed before all the people. Richard of San Germano says that some of the Patarenes were converted back to the orthodox faith, while others were burned.63 That same month, Gregory issued a new set of statutes regulating the investigation, prosecution, and punishment of heretics that was modeled on earlier examples of anti-heretical legislation. The edict called for the lifetime imprisonment of unrepentant heretics, barred them from holding public office, and anathematized their supporters. If they impeded proceedings against such “infamous” persons, judges and notaries should be deprived of their positions. The law banned the clergy from administering the sacraments to heretics or their supporters, taking alms from them, or giving them ecclesiastical burial. It also forbade clerics to dispute in “public or in private” with lay people about the catholic faith. Anyone who knew about the “hidden meetings” of heretics should tell their confessor or someone else who might notify their bishop.64 In conjunction with the pope’s efforts, the Roman senator Annibaldo, demonstrating the shared interest of clerical and secular authorities in wiping out dangerous heretics, issued a set of municipal statutes against heresy at the same time, committing himself under oath to prosecute heretics identified by the church’s “inquisitors.”65
Gregory’s pursuit of heresy did not stop with the city of Rome. Later that year, while collecting still outstanding debts from the War of the Keys from communities in Campagna, he took action against the lords of the commune of Miranda, who were known by “public infamy” to be “supporters of heretics, violators of public roads, forgers of papal bulls, and counterfeiters of coins.” After a siege of the town undertaken with allies from Rieti, Alatrin, a papal chaplain and rector of the duchy of Spoleto, met with Miranda’s leaders and other witnesses called by a herald to the Church of Saint Mary in Terni. He received their surrender on the pope’s behalf, taking the commune under the direct lordship of the Roman church.66 In September 1231, Gregory issued the first of several warnings to Ezzelino da Romano, the father of the young warlord by that same name, calling him a “public protector” of heretics and causing an “enormous scandal in the general church.” The pope recounted his personal meeting with the senior Ezzelino years before, during his legation in Lombardy in 1221, which led to a tearful scene when Ezzelino deceitfully declared his devotion to the church and hatred for the “heretical depravity.” Gregory gave him two months to appear at the curia to answer for such charges and show his obedience to the church’s commands. Otherwise, the pope would call upon the faithful to take actions against him, including occupying his lands and seizing his goods.67 The Roman pontiff’s support for the preachers of the Great Devotion—whose message of peacemaking included sermons against heresy and, on occasion, the burning of heretics—might have stemmed in part from his interest in opposing heresy through cities and communities of northern Italy.68
As the occupant of the Apostolic See, the pope’s duty to oppose heresy extended beyond the Papal States and Italy. In principle, it reached throughout the universal church, wherever heretics might be lurking among orthodox Christians. In 1231, Gregory forwarded copies of both his and the Roman senator’s antiheretical edicts to other communities outside of Italy, calling upon prelates to publicize solemnly their contents once a month in their dioceses and to make sure that local secular judges and officials implemented and enforced those regulations.69 The pope’s widely circulated calls for action against heretics, bulls like Illi humanis generis and Vox in Rama, painted a vivid portrait of heretical communities gathered in secret for foul rites, such as holding orgies, worshipping black cats, being visited by a diabolic “pallid man,” and tossing the Eucharist in the privy after mass, among other foul deeds.70 To prosecute the war on heresy, Gregory, rather than just relying upon poorly trained or lukewarm local bishops, authorized figures such as the Premonstratensian canon Conrad of Marburg to take the lead in searching for heretical communities. Above all, he turned again to the mendicant orders, the Franciscans and especially the Dominicans, whose commitment to fighting heretics had started with their founder.71 Although the papal curia did not direct the daily activities of their investigations, such inquisitors publicly embodied papal authority, displaying letters and “written mandates” bearing the seal of the Apostolic See that empowered them to act in towns, cities, and parishes throughout Europe.72
As part of this campaign against heresy, Gregory publicly validated the antiheretical measures promoted by Frederick II, which were enshrined in the emperor’s coronation
