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 crusading oath gave Gregory the excuse he needed to humiliate and depose the imperial ruler. “Pope Gregory felt himself by stern necessity compelled to compass the destruction of the Hohenstaufen,” Ernst Kantorowicz writes. “He seized the first opportunity of compelling the foe to fight.” Others offer similar appraisals. For Gregory, who “knew little of conciliation or peace,” Thomas Van Cleve claims, “the crusade per se was far less important than it had been to Honorius III. It was, indeed, secondary to a much more ambitious goal: the complete triumph of the papacy over the Empire in the struggle for predominance in Christendom.” Or, as David Abulafia puts it, Gregory was “keen to indicate from the start the absolute primacy of his office over that of the emperor…. With his election, cooperation between the pope and emperor gave way to the idea of the subordination of emperor to pope.”2
And yet, judging by Gregory’s repeated declarations and actions, the crusade mattered immensely to his conceptualization of the papal office, forming a public red line between him and the emperor. After generations of summoning crusades, the Roman church had invested vast amounts of spiritual, political, and material capital in the unrealized goal of defeating the so-called Saracens and securing the holy places once and for all. As seen above, during his time as a cardinal legate, Hugolino dei Conti had devoted himself to the project of freeing Jerusalem. As pope, he became responsible for crusading at an especially critical juncture in its history, when disappointment and anxiety about crusading failures reached new levels due to the collapse of the Fifth Crusade. As his predecessor Honorius had warned Frederick and other notable figures on more than one occasion, the Christian people “murmured,” “clamored,” and made “public complaints” about the failure of their leaders to take up the business of the cross and work together to free Christ’s patrimony. Now Gregory faced those same outcries. The need to find a solution to Jerusalem’s captivity had never been greater, or at least,