Communicating Excommunication
On 19 September, Pope Gregory confirmed Frederick’s self-inflicted sentence of excommunication at Anagni. As one of Frederick’s modern biographers wryly observes, excommunication represented an “occupational hazard” for medieval emperors.18 Gregory IX’s anathematizing of Frederick II, however, hardly represented a run-of-the-mill excommunication, if there ever was such a thing. It placed the pope and the most powerful ruler in Europe publicly at odds during a moment when the fate of Jerusalem seemed to hang in the balance.19
Gregory’s anonymous biographer, a member of the curia with close ties to the pope, describes the scene of the emperor’s solemn excommunication in the Life of Gregory IX.20 Gregory had come to his hometown in July. The bishops of Rome commonly left the city during the summer months to escape the heat. On 18 September, no doubt anticipating his plans for the following day, he elevated six presumably supportive clerics from the curia to the college of cardinals, promoting, among others, Sinibaldo Fieschi—the future pope, Innocent IV—as cardinal priest of San Lorenzo in Lucina.21 On the Feast of the Archangel Michael, assisted by the cardinals and other archbishops and bishops and wearing his pontifical robes, Gregory delivered a sermon in the city’s cathedral church on the Gospel of Matthew 18: 7: “For it must be, that scandals come to pass, but woe to the man by whom that scandal comes.” After delivering multiple warnings to Frederick about the need to fulfill his vow, the pope, like the “archangel triumphing over the dragon,” had “publicly announced” Frederick’s excommunication, affirming the sentence incurred when he had failed to depart on crusade as he had sworn to do at San Germano. Although the author of Gregory’s vita does not say so, the solemn ceremony must have closely followed the guidelines for excommunication and anathema from canon law, including twelve priests holding lit candles, throwing them on the ground, and stamping them out.22
In canon law, the rules for excommunication give instructions for a letter to be sent throughout the appropriate parish announcing the sentence. In this case, the “parish” constituted nothing less than the entirety of Christendom.23 The papal letter In maris amplitudine shows this messaging campaign at work. Issued on 10 October, the encyclical opens by describing the tempests that menaced the ship of Saint Peter on the storm-tossed seas: the “perfidy of the pagans” in the holy places; the “frenzy of tyrants” assailing the liberty of the church; the “madness of heretics” tearing Christ’s “tunic” asunder; and the “perversity of false sons and brothers.” For this reason, the Apostolic See had elevated and supported Frederick since his boyhood to act as a defender of the church. When he traveled to Germany to receive his crown, he had assumed the cross, a source of hope for the Holy Land. When crowned emperor “by our own hands, although in a lesser office,” Frederick had “publicly” renewed his vow, planning to leave on crusade two years later. When the deadline drew near, however, with “many excuses,” he had failed to depart. At San Germano, he had bound himself by another such oath, promising to make his passage by August two years later. The legates on hand, “publicly by the authority of the Apostolic See,” had authorized a sentence of excommunication that would be triggered if he failed to meet these obligations. Now he had done so. Gregory’s letter describes the gathering of the crusader army at Brindisi and its decimation by the summer heat, disease, and desertion, followed by the emperor’s failure to depart for Syria, which left those crusaders who did set sail leaderless and endangered the Holy Land to the emperor’s shame and the “shame of all Christendom.” After lamenting the conditions overseas and emphasizing his commitment to the crusade, the pope had “unwillingly but publicly” pronounced the emperor as excommunicate, commanding him to be “shunned by all” and instructing prelates to announce his status publicly and gravely proceed against him if his stubbornness persisted.24
It is hardly surprising that this product of the papal chancery offers a onesided picture of Frederick’s actions. That was the point: to sway opinions and trigger indignation, leaving no room for doubt about the rightness of Gregory’s decision. As intended, In maris amplitudine circulated widely, having been sent to prelates in Italy, Germany, England, and elsewhere. In his Flowers of History, Roger of Wendover includes a version of the text sent to Stephen, the archbishop of Canterbury. Roger did more than just “copy” or “transcribe” the letter. He narratively framed the letter, describing the pope’s decision to anathematize the emperor by relating how Gregory “ordered the sentence of excommunication to be published in every place through apostolic letters.” Other chroniclers offer similar observations about how the pope commanded Frederick “to be denounced throughout the empire,” how he sent his “general letters throughout the entire west” regarding the emperor’s public excommunication, or how he denounced the emperor “as excommunicate throughout the western church, through his letters sent to all the prelates, that is, archbishops, bishops, and archdeacons, so that they might denounce him in their dioceses.”25
The emperor responded by sending out his own “excusatory” letters, including the encyclical In admiratione vertimur. This product of the imperial chancery lamented the unforeseen devastation of the crusading army at Brindisi, explaining the circumstances of Frederick’s delayed passage overseas and complaining about the pope’s “unjust” judgment. The emperor wanted the “entire world” to hear about his innocence and his grievances against Gregory, whose letters tried to “raise up hatred” against him in every land. In admiratione vertimur replays more or less the same version of events as In maris amplitudine, but in a different key, showing how Frederick tried to honor his crusading vow from the beginning, despite the Roman church’s half-hearted attempts to protect and to assist him since his boyhood. Disregarding his doctors’ orders, he had traveled to Brindisi and even set sail for Syria before his near-fatal illness forced him to debark. Fully intending to head overseas the following May, he had sent ahead numerous galleys and soldiers along with funds to support them, fulfilling his other obligations made at San Germano two years earlier. In the closing portions of this encyclical, Frederick gave instructions for the letter to be “read aloud and heard in public.”26 Richard of San Germano describes how the emperor sent one of his officials, Roffrid of Benevento, to do just that on the Capitoline Hill in Rome. In his Flowers of History, Roger of Wendover explains that “just as the pope had the issued sentence published in every Christian land, so the aforesaid emperor wrote to all of the Christian kings and princes complaining that the sentence had been injuriously passed against him.” Roger relates that another such letter, sealed with Frederick’s golden bull, arrived at the court of Henry III and warned the English king that Gregory wished to make all rulers into his “tributaries.” Responding to both sets of letters, Henry tried to carve out a middle ground between the two sides for the good of the holy places, beseeching the pope to show compassion for the emperor and calling on Frederick to reconcile with the Roman church as soon as possible. This was not the last time he would find himself in this uncomfortable position.27
Chroniclers and annalists from every corner of Europe followed these astonishing events, implying or openly revealing their sympathies in the matter. The Guelf Annals of Piacenza, so-called to designate their anti-imperial bias, describe how Frederick’s failure to depart overseas provoked Gregory to “publicly anathematize and excommunicate the emperor before all of the people who had come to visit the threshold of