Although Frederick indeed left for Germany to confront his rebellious son, other sources claim that he left a sizable force of troops behind at Viterbo to support the pope. Over the summer, Gregory began to widen his appeals for armed help against the Romans well beyond those he made to the emperor. In July, he wrote to the cities of the Lombard League, stressing this need to employ the “ministry of the imperial arm” in defense of the church and calling upon them not to impede the transit of Frederick’s forces. At the same time, still in the middle of peace negotiations between the Lombards and the emperor, he assured them that he would not abandon their interests.91 The following month, the pope informed the cities and leaders of Tuscany about the appointment of Rainier of Viterbo, cardinal deacon of Santa Maria in Cosmedin, as the leader of the assembling papal army, which was intended for the defense of the papal patrimony and the liberty of the church. A few months after that, Gregory directed a letter to Siegfried, archbishop of Mainz, reminding him about an oath he took to protect the Patrimony of Saint Peter, instructing him to come with or send troops by the following March.92
Around this time, the “pope’s army” and the “emperor’s army,” as Roger of Wendover describes the two forces, coordinated their assaults on the outskirts of Rome, destroying a number of surrounding villages. Roger tells us that Gregory also gave Peter, bishop of Winchester, a leadership role in the papal army, valuing him for his military skills and riches, not to mention the contingent of English foot soldiers and bowmen he brought with him. Later in October, when a large body of Roman troops made an undisciplined sally against Viterbo, the pope’s combined troops delivered a crushing blow against them, killing thousands and taking many more captive. As Matthew Paris adds in his History of the English, elaborating on Roger’s account, the slaughter was so great that “the hearts of Pagans rejoiced, far and wide.”93 The Romans never recovered from these defeats, although they sent a defiant message by passing a series of edicts that condemned Rainier of Viterbo and banned the pope from returning to Rome until he paid a large indemnity for damages caused during the war.94
During the following months, Gregory continued to solicit armed support from every corner of the Christian world, calling upon Eberhard, archbishop of Salzburg, and thirty-two other German bishops to provide troops with stipends for three months of service. He made a similar request to the archbishop of Rouen and nineteen other prelates in France and Spain, denouncing the Romans, who “ought to be special sons of the church, but, degenerating from sons into stepsons, are showing themselves to be disloyal and ungrateful, so that scarcely a spark of loyalty or gratitude remains among them.” In this letter, the pope identified the rebellious Romans’ desire to “enslave the Roman church,” not only by seizing its temporal goods but also by abusing its spiritual persons and offices, as a “public not private” problem.95 Closer to home, Gregory summoned the citizens of Velletri to the service of the Roman church, promising “the full remission of sins for those who made confession with a contrite heart.”96 The pope also took specific measures to raise funds for his campaign against the Romans while depriving the city of its own financial resources. In December 1234, citing the “malice of the Romans,” he instructed bishops in the kingdom of France to retain all revenues from benefices belonging to absentee Roman clergy, excepting papal chaplains, and to send the proceeds to Master Simon, an official from the papal chancery. In a similar letter to the archbishops of Canterbury and York, Gregory instructed them to forward such funds to the Templar master at Paris. The Tewksbury Annals record that some Romans were in fact deprived of their benefices, the revenues of which were forwarded to Canterbury.97
Whether the money in question ever reached the pope is unclear. There is little evidence that bishops besides the opportunistic Peter of Winchester provided serious logistical support, in terms of either troops, funds, or supplies. Nevertheless, by the spring of 1235, Gregory’s overall efforts had worked, bringing his opponents to the bargaining table. In April and May, the pope’s legates in Rome—Romano, the cardinal bishop of Porto, John de Colonna, and Stephen Conti—negotiated peace terms with a new senator, Angelo Malebranca, and other leaders of the city, receiving their solemn oaths to render satisfaction to the Roman church and the emperor during a public ceremony staged on the Capitoline. Frederick had already given his approval to the plans for peace, assuring the pope of his support, even if he could not be on hand in person. Captives were released on both sides. Gregory soon returned to Rome.98
Compared to the pope’s ambitious plans for the next crusade to the holy places, or even his past calls for assistance against Frederick’s forces in the Regno, Gregory’s efforts to pitch an armed campaign against the citizens of his own city as a shared responsibility of all Christians seems to have had limited publicity and minimal impact. The pope never called for a direct subsidy or special tax to fund his campaign against the Romans, perhaps due to lingering complaints about his levies on clerical incomes in 1228, which had been raised to pay for his campaign against Frederick in the Regno after the emperor’s excommunication. Nor did he authorize any sort of preaching campaign to drum up support for this struggle against the “pride of the Romans.” There are no signs that the papal army directed against the Romans marched under the sign of the cross or even under the banner of the keys, an indicator of the limits on how far the papacy could push such spiritually and politically charged symbols in public. Beyond Matthew Paris’s sardonic comment about the joy brought to pagans by Christians killing each other, it remains difficult to determine what this war with the Romans meant for contemporaries increasingly habituated to hearing papal calls for military action in defense of the church. Judging by their silence, many chroniclers ignored the fighting between the Roman pope and the Romans, or perhaps never heard much about it.
In this regard, Gregory’s struggles with the Romans remained to a large extent a local affair rather than a concern for the entirety of Christendom. But the episode nevertheless remains an important and telling one. The papal campaign against the citizenry of Rome once again reveals the capabilities of the thirteenth-century papacy to publicly authorize violence in defense of the church, even against orthodox Christians: promising the remission of sins for those serving the papal cause and taking them under the “special protection” of the Apostolic See, styling the fight as a common challenge for the entire church, and attempting to draw upon ecclesiastical resources from around western Europe. Every time the pope became involved in any sort of military action, it mattered for the wider Christian community, possibly reaching into their pockets and disrupting their lives. Gregory’s fight with the Romans also demonstrates how Italian problems, so to speak, could become everyone’s problems. In this instance, the pope and emperor stood on the same side of the fight. Moving forward, that would not be the case.
Writing to Gregory from Worms in late July, Conrad, bishop of Hildesheim, expressed the joy felt by the “universal Christian people” that peace had returned to the Roman church after an end to the pope’s hostilities with the city of Rome.99 Through that settlement, there lay “hope for future tranquility and peace for all churches.” Conrad also shared news about Frederick’s marriage to Isabella of England, King Henry III’s sister, earlier in July. During the matrimonial negotiations, Gregory had supported Frederick and Isabella’s union. He may have even first suggested it as a means to ally the English crown and Roman empire—one more way of promoting the peace and furthering the cause of the new crusade. Frederick’s son Henry had attended the ceremony, having been received back into his father’s good graces, his rebellion at an end. (In fact, Frederick soon banished Henry to the Regno, where he died in 1242 after years of captivity.) Conrad concluded that the emperor and other magnates gathered for the wedding would be heading next to Mainz to hold an assembly on 15 August, a convocation intended for “the general good of the peace and the benefit of the entire church.”100
For years, despite the undeniable stresses and strains placed upon the relationship between their two offices, the pope and emperor had maintained a public state of concord between the two powers, preserving their agreement struck at San