War with the Romans
In May 1234, Frederick made a personal appearance before Pope Gregory, who was then staying at Rieti. During this meeting, they discussed the unsettled conditions overseas in the holy places, but they also spoke about more pressing business. According to the pope’s biographer, Fredrick came as a supplicant, bringing his son Conrad with him and seeking assistance against his other son, Henry, the king of Germany, who had rebelled against his father. Gregory likewise had reasons for welcoming Frederick. Much like the emperor, he faced his own problems with inside agitators who questioned his authority as the lord of the Papal States and bishop of Rome, in this case facing an uprising by the inhabitants of his own city. This meeting at Rieti set the stage for perhaps the most unexpected and understudied episode of public cooperation between Gregory and Frederick during the years after the peace of San Germano, as the two former opponents agreed to assist each other against their present enemies.78
Historians generally view this alliance as one of undisguised convenience: the pope aiding the emperor against his traitorous son, the emperor assisting the pope to wage war against his own city. This convergence of Gregory’s and Frederick’s interests, however, should not be dismissed as merely opportunistic. Much like the papal promotion of other common causes with the emperor, such as freeing Jerusalem and wiping out heresy, Gregory’s turn toward the “material sword” represented an advantage of the peace between the two powers. While the pope mobilized Christians to fight for the common cause of defending the Roman church’s liberty, Frederick could fulfill his imperial duty as that church’s primary defender. To some extent, the war with the Romans validated the harmony between two powers, even if the results of their cooperation fell short of papal expectations. At the same time, Gregory’s war against the Romans with imperial aid raised complaints about the pope’s use of ecclesiastical resources to field a “papal army” on the Italian peninsula. Much like the War of the Keys, the pope’s fight against the Christians of his own city did not sit well with everyone.
Gregory hardly represented the first pope to experience troubles with Roman aristocratic factions and communal government, a problem shared by generations of his papal predecessors. But as Peter Partner observes, his relations with the city were “notoriously bad.”79 As seen in the previous chapter, after the pope repeated Frederick’s sentence of excommunication in the basilica of Saint Peter in 1228, a mob had driven him and several cardinals out of the church and eventually out of the city. By the time that the Gregory and Frederick agreed to the Treaty of San Germano, the pope had more or less made peace with the citizens of Rome, who had been “assailing the churches of the City and harassing the Patrimony’s vassals with various burdens,” as the author of the pope’s vita describes the situation. He also claims that the flooding of the Tiber in winter 1230, clearly a punishment from God, convinced the Romans to change their wicked ways. However, problems persisted between the Roman pontiff and the Romans due primarily to the city government’s territorial ambitions in central Italy. In the spring of 1231, Roman forces attacked Viterbo, part of the papal patrimony, and seized the town of Monteforte, near Naples, the following summer, using it as a base to “subjugate the remainder of Campania to their dominion.” In June 1232, Gregory left Rome for Rieti, not only to escape the summer heat but also because of his growing tensions with the Romans.80
During this episode of conflict with the civil government of Rome, the pope turned to Frederick for help, seeking his assistance against the “pride of the Romans.” At Gregory’s request, the emperor took Viterbo under imperial protection in 1231 and tried to ensure that the Viterbans would cooperate with papal legates assigned to broker a peace agreement, Thomas of Capua and Raynald da Jenne. Throughout his correspondence with Frederick relating to this situation, Gregory emphasized the emperor’s role as the defender and advocate of the Roman church, who was responsible for protecting its rights, which were indelibly linked to those of the empire. At an especially evocative moment, he described his joy that the “imperial right hand” brandished the “triumphal sword taken up from the body of blessed Peter, received from the hand of Christ’s vicar,” wielding it vengefully against such malefactors. On more than one occasion, Gregory enjoined Frederick by the “remission of sins” to aid the Roman church.81 In one of his replies to the pope, Frederick expressed similar sentiments, remarkably describing the ultimate unity of the “two swords,” the spiritual power of priests and the temporal power of emperors, formed from one substance and joined in the “sheath” of the church.82
Despite these promises, actual military aid from the emperor was not forthcoming. Facing an uprising in Sicily, Frederick returned to the Regno with his forces in the late fall of 1232, leaving the pope to make peace with the Romans as best as he could. In letters sent to Frederick the following February, the pope described his earlier satisfaction when the emperor’s envoys had informed him that Frederick was “manfully preparing to fight in defense of the faith, for the preservation of ecclesiastical liberty, and for the preservation of Saint Peter’s Patrimony.” Subsequently, Gregory heard rumors that Frederick planned to return to the Regno, abandoning his obligations as the defender of the church. In closing, the pope called upon him to fulfill his duties with “deeds, not just words.”83 Gregory’s biographer, looking back at these events after 1239, when the pope excommunicated Frederick for the second time, claims that the emperor never really intended to help the church but instead secretly conspired with the Romans against the pope.84 Through a series of negotiations led by the cardinals Thomas and Raynald, who smoothed things over by cash payments to the Romans, the pope nevertheless helped to forestall the assault on Campania. In March 1233, representatives from Rome approached the pontiff while he was staying at Anagni and begged him to return to the city. A few months after that, the pope helped to broker a truce between Rome and Viterbo in which the Romans forgave any damages caused by the Viterbans during the recent fighting and the Viterbans swore fealty to the Romans, both sides releasing their captives.85
By the spring of 1234, however, this peace between the pope and the Romans began to deteriorate again. According to Gregory’s biographer, a new senator named Luke Savelli renewed the city’s military push into the surrounding regions and issued statutes “damaging the liberty of the church and causing enormous harm to the Apostolic See,” trying to enslave the papal patrimony and overturn its privileges that dated back to the days of Emperor Constantine.86 By this time, news of the discord between the pope and the Romans had begun to make an impression on wider audiences around Christian Europe. Roger of Wendover, for example, describes how the Romans tried to “usurp” ancient rights in Rome, seeking among other things immunity from excommunication and interdict, a demand that the pope refused. While lesser than God, as Saint Peter’s heir and their spiritual father he possessed the right to stand in judgment over them. By May, the pope again left Rome for Rieti, where he passed a sentence of excommunication against Luke Savelli and several other leading Roman citizens due to their seizure and fortification of Monte Alto, a town belonging to the Patrimony of Saint Peter; their taking hostages from that same community; and their extraction of oaths from papal vassals, all actions contrary to the interests of the Roman church.87
At Rieti, Gregory also began to make plans for a coordinated assault on the “rebellious Romans,” assisted by the emperor, who placed himself “at the service of the church” against the citizens of the city.88 Neither the pope nor the emperor dissembled the fact that Frederick expected help against his rebellious son, who was allied with some of the Lombard cities in resisting Frederick’s rights. In July, Gregory wrote to the archbishop of Trier and other German prelates, denouncing Henry for violating his promises of fealty to his father and instructing the bishops to publicize Henry’s excommunication throughout the kingdom. He specified that the prince’s actions triggered the suspension of any oaths rendered to him by ecclesiastical and secular magnates.89 The anonymous author of the Life of Gregory IX, writing after 1239 with retrospective disapproval of the emperor’s every action, claims that Frederick arrived uninvited at Rieti, offering his son Conrad as a hostage and pledge of his commitment to the understandably suspicious pope—a