In his most recent book, The Two Powers: The Papacy, the Empire and the Struggle for Sovereignty in the Thirteenth Century, Brett Whalen addresses a familiar theme in medieval history, the conflict between the spiritual power of the church (sacerdotium) and the temporal ruler (regnum). This book provides an innovative approach to the complex and contentious relationship between the Papacy and the Empire in thirteenth-century Europe. Whalen argues that medieval Christendom was a dynamic interaction of texts, people, and rumors that participated in "shared performances" (7). Conflicts between the two powers over sovereignty played out in public, and the spiritual authority of the papacy was put into political action in pursuit of the common good. This reconceptualization asks the reader to consider the public aspect of medieval Christian society and its impact on claims of papal sovereignty, thus providing deeper insight into the "public nature of Christendom in the Middle Ages" (6).
The book is divided into two main parts with short bridge chapters that serve as introductions to each part. The first chapter called "Prelude. The Legate" opens with a description of the coronation of the young Hohenstaufen king of the Germans, Frederick II. Already king, Frederick received the imperial crown from Pope Honorius III (r. 1216-1227) in 1220 making him emperor of the Romans. Behind this picture of cooperation, there were major conflicts in northern Italy between the Lombard League and Frederick; and in the south the Emperor clashed with the pope over issues of governance of the Regno (Sicily, Calabria and Apulia). In between these two areas of the Italian peninsula were the Papal States, which were surrounded on both sides.
Prior to his coronation the Emperor had taken a vow to lead a crusade to the east but his promise remined unfulfilled at the death of Honorius in 1227. An ardent supporter of crusade, the newly elected pope, Gregory IX (r. 1227-41) reminded Frederick of his public vow and when the assembled crusaders failed to depart in the summer of 1227, Gregory excommunicated Frederick. Prominent scholars have argued that this episode was an opportunity for Gregory to strike a blow against the Emperor and further papal sovereignty. Whalen interprets this event differently, arguing that right up until the planned departure of the crusaders the pope was on good terms with Frederick, adopting a "pastoral--if perhaps, paternalistic--tone" (23). Citing several chronicles and other primary sources, Whalen argues that the public nature of the propaganda on both sides was designed to provide each party with "leverage" ahead of pending peace negotiations, and not ideological claims of superiority.
Frederick embarked on his long-promised crusade in 1228 while still bound by excommunication, and the Emperor secured lands in the east, negotiating a ten-year truce in 1229 with Sultan al-Kamil, which handed over Jerusalem to Latin control. Trouble at home called Frederick back from the east and his return was met by the reality that papal troops had turned many of his loyal vassals away from him in the Regno in southern Italy. Rather than challenging the papal troops, Frederick backed down and agreed to make peace with the pope. The result was the Peace of San Germano that was formalized near Monte Cassino in July 1230, which was followed by Frederick's absolution in August. This settlement ushered in five years of peace that led to Gregory and Frederick working together on both crusading and combating heresy; the pope "publicly validated the anti-heretical measures promoted by Frederick II" (62). This five-year period of peace demonstrates that the two powers could work together in pursuit of common objectives.
Trouble in northern Italy between the Lombard League and the Emperor led to an end of the period of cooperation when Frederick invaded Lombardy in the fall of 1236. This prompted the pope to invoke the Donation of Constantine in a letter to Frederick which asserted that "Christ's priests are held to be masters and fathers of kings" (85). Calling on such an incendiary document prompted many modern historians to view this as a statement of papal superiority. However, Whalen asserts that this was not an ideological claim, but rather, an admonition to the emperor not to interfere with the pope's ecclesiastical privilege of "fullness of power" which he exercised over the church. Whether one agrees with this interpretation, it is a clear indication of the pope's support for the Lombards and this coupled with a new plan for a crusade led to a fracture that resulted in a second excommunication of Frederick in 1239. After constant struggles with Frederick including the Emperor's attack on ecclesiastical officials travelling to the pope's proposed council, the aged pope died in 1241 with no resolution in sight.
Part II of the book begins with the "Interlude. The Vacancy" which highlights the interregnum, a period before the election of Pope Innocent IV (1243-1254). After his election, a cautious peace existed between Innocent IV and the Emperor; however, circumstances in Italy were still problematic and a horrific conflict over Viterbo led to a breach with the new pope. Frederick lost the city but seemed in the peace-making mood and in March 1244 imperial envoys agreed to a list of papal demands that would restore things as they had been prior to Frederick's excommunication in 1239. But when the pope learned that the Emperor was planning on invading Lombardy as soon as the ban was lifted, his worst fears about Frederick were confirmed.
In the summer of 1244, Pope Innocent left Rome, moving to Lyons to distance himself from the Emperor's reach. The pope called a church council to deal with Frederick and to establish a public case for the eventual deposition of the Emperor. In the summer of 1245, the Council of Lyons met in three sessions, re-confirming Frederick's excommunication; the third session passed a sentence of deposition. This effectively deprived Frederick of his lands and lifted the oaths of Frederick's vassals. The pope went further, calling a crusade against Frederick and promising indulgences for those who accepted. This is often identified as the first fully developed "political crusade," but Whalen explains that the picture is more complex (186). Crusading offered special benefits for both clergy and nobles and by the middle of the thirteenth century it, "had become the hallmark of the pope's spiritual and worldly sovereignty" (206).
The battles between Innocent and Frederick left the papacy with huge debts and no resolution. With Frederick deposed and his heirs ineligible to inherit the throne, the pope called on the German electors to select a new king. They elected two anti-kings, initially Henry Raspe, who died in 1147, and then William of Holland. When Emperor Frederick II died 1250, Pope Innocent offered the imperial crown to William. Not keen to give up the political leverage the crown gave him, Innocent never crowned him emperor, and by the time the pope was serious about conferring the crown, no one would take it. The position remained vacant for thirty years. Frederick's heirs, Conrad and Manfred, did not go quietly, and they refused to acquiesce to their father's rival. Finally, in 1266, Pope Clement IV asked Charles d'Anjou to accept governance of the Regno and at the Battle of Benevento, he killed Manfred, the final member of the Hohenstaufen line.
This book is well written and contains an enormous amount of information. The author does an excellent job with the dense and complicated material and it is a welcome addition to the sparse secondary literature available on Pope Gregory IX in English. The excellent use of primary sources provides a variety of perspectives, and chroniclers such as the English Benedictine, Mathew Paris, and Italian Franciscan, Salimbene of Adam, give the reader insight into past events. The author does a brilliant job setting these sources into historical context and he demonstrates a deep knowledge of the period. Helpful maps included at the front of the book provide the reader with a visual reference for events. One helpful addition would have been a comprehensive timeline to help keep track of the major events discussed in the book. However, clear chapter divisions and excellent use of subheadings provide helpful signposts for the reader.
This is a must-read for those interested in medieval political thought or the way religious claims of sovereignty were made in medieval Christendom. The audience for this book is broad, and it will appeal to motivated undergraduates, graduate students and medieval scholars. Brett Whalen presents an insightful, nuanced and learned account of the struggles between the pope and Emperor in the thirteenth century. His fair-minded approach demonstrates that this conflict took place in public and was historically contingent rather than a battle of opposing ideologies (3).