party. For excommunication and interdict to possess real political and social consequences, they required deliberate publicizing, such as the repeat performance of ritual anathema on Sundays and feast days, with the clergy gathered in church denouncing the sinner and casting down lit candles and extinguishing them. Letters were sent around the diocese, publicizing the ban.20 To meet the conditions for absolution, the podestas of Piacenza, Treviso, and Faenza swore “public oaths” with hands on the Gospels during assemblies in the communal hall or bishop’s palace. During such gatherings, the “lovers of peace and concord” swore to “obey the commands” of the Roman church, to renounce further “rancor” or “quarrels” or “vengeance,” and to release captives, pay fines, and drop any further appeals to the legate, the pope, or the emperor. Notaries on hand recorded these acts, producing and sealing the “public instruments” that memorialized the terms of the agreement.21 But things did not always go as planned. Writing back to Hugolino about the unresolved dispute between the Milanese and their archbishop, the bishops of Bergamo and Lodi described a raucous meeting in which the assembled citizens refused to hear the charges leveled against them, protesting when the two prelates tried to read aloud the legate’s letter detailing their misdeeds. Lasting peace always seemed to be elusive, although any peace remained preferable to scandal, discord, and war.22
During the course of his legation, Hugolino identified an especially subversive threat to the peace: heretics hiding among the faithful and undermining the church from within, waiting to burst into the open. Who were those supposed deviants? After decades of experimentation in religious life among the laity, especially among women and men living in urban areas, the line between orthodoxy and heresy could be sometimes hard to discern. Some new groups, like the recently formed mendicant orders, the Franciscans and Dominicans, secured legitimacy through formal recognition by the church. Hugolino knew this better than most, serving as the first cardinal protector of the Franciscan order starting in 1218.23 Others, like the Waldensians, whose commitment to poverty and apostolic living did not look all that different from that of the mendicants on the face of things, fell on the wrong side of the church’s determination between right and wrong behavior and belief. Scholars still debate over the identity—or, according to some, even the existence—of so-called Cathars, loosely defined as subscribers to a dualist cosmology with a pronounced streak of anticlericalism. In other instances, refusing to obey the commands of the Roman church could shade from a question of discipline into heresy, such as when excommunicate persons refused to acknowledge their status and thereby became “despisers of the keys,” rejecting the clergy’s power to loosen and bind sinners.24
By the time of Hugolino’s legation to Lombardy in 1221, the fight against heresy had emerged as a prominent area of convergence between the interests of popes and emperors. The third canon of the Fourth Lateran Council, modeled after earlier legislation, had instructed bishops to investigate accusations of heresy in their dioceses with the help of secular authorities, calling up upon officials to brand heretics as infamous, to confiscate their goods, to bar them from public office, and when necessary to carry out capital punishment against them.25 As seen above, at his coronation Frederick II affirmed his own commitment to battling “Cathars, Patarenes, Leonistas, Speronistas, Arnaldistas, Circumcisers, and all heretics of either sex, by whatever name they are called.” As part of his legate’s duties, Honorius expected him to ensure that the schoolmasters at Bologna add Frederick’s constitutions to the law books, including his statutes against heresy of all kinds. Hugolino likewise insisted that communes in the region enter those same constitutions into their civil law codes along with the anti-heretical measures promulgated at the Fourth Lateran Council. At Piacenza, as part of the newly established peace, he specifically called upon both the popular party and militia to expel all heretics from the city and confiscate their property. During a public gathering at Mantua, summoned by ringing bells and trumpets at the legate’s request, the civil authorities agreed to ban all heretics, giving them eight days to leave the city or face a penalty of one hundred imperial pounds. A herald proclaimed this policy on a bridge over the river Mincio in the middle of the city.26
Crusading, peace, and the fight against heresy: this trifecta that gave shape to Hugolino’s legation in 1221 would continue to define the public commitments of his papacy years later. His time as a legate demonstrated the visible and audible ways that the authority of the Apostolic See reached communities beyond the orbit of the papal curia, through the travel and presence of the pope’s representatives (or even the representatives of the pope’s representatives), through the circulation of letters and other documents, through the convocation of crowds and assemblies, through face-to-face meetings, and through the ritual proclamation of excommunications, sentences of interdict, and scenes of absolution. As a papal legate, Hugolino enjoyed the open support of the newly crowned Roman emperor, who had been signed with the cross by the cardinal’s own hand. As he began his return journey to Rome in October, the bishop of Ostia and Velletri had no way of knowing that the crusade to free the holy places, envisioned and publicized as a common enterprise for the papacy and the empire, would become a source of tension, distrust, and eventual antagonism between the emperor and himself after his own elevation to the highest office in the church.
PART I
Gregory IX
Chapter 1
A Contested Vow
Just one day after the death of Pope Honorius III on 18 March 1227, the cardinal clergy assembled at the Septizodium palace in Rome elected Hugolino dei Conti, cardinal bishop of Ostia and Velletri, as the next bishop of Rome. The new pontiff, then about seventy-five years old, took the name Gregory IX. As was customary, a few days later the pope dispatched a letter notifying “the entire world” about his elevation to the Apostolic See, sending that missive to prelates, nobles, and Christian rulers everywhere, including Frederick II, emperor of the Romans and king of Sicily. In addition to the news of Gregory’s election, this announcement made one thing plainly clear: the pope’s commitment to the upcoming crusade that was supposed to depart the upcoming summer. In the version of his letter sent directly to Frederick, which stressed his past affection for the prince while holding a “lesser office” as cardinal bishop, Gregory called upon the Hohenstaufen ruler to prepare himself “manfully and powerfully” for the upcoming passage to the Holy Land, reminding him about all of the pope’s labors in the past to support crusaders.1
Over the following months, Frederick’s unfulfilled crusading vow would become the source of a public crisis between the new pope and the emperor. By August, a force of crusaders gathered at Brindisi intending to accompany the emperor to Syria, but when pestilence struck the army, killing many and seriously sickening Frederick, he decided against sailing for the holy places. On 19 September, Gregory excommunicated him or, more accurately, formalized his excommunicate status, which had been automatically incurred by the violation of his previous oath to depart on crusade that summer. By doing so, the pope placed his priestly office at odds with the Christian emperor, a sworn crusader and vassal of the Roman church. Their confrontation continued even after the emperor left on crusade in 1228, still excommunicate, and persisted during Frederick’s time in the Holy Land. In the meantime, Gregory widened his accusations against the Hohenstaufen ruler and his officials in the Regno, denouncing their abuses of the church’s liberty, attacks on papal supporters, and what might now be called war crimes—allowing Muslim mercenaries to torture and kill priests. To oppose Frederick, Gregory eventually gathered a papal army and coordinated a military campaign against the emperor’s supporters in southern Italy that was waged under the “banner of the keys,” the sign of the pope’s spiritual power as the head of the church and status as the temporal lord of the papal patrimony.
According to many scholars, Frederick’s violation of his
