Although the relationship between Gregory and Henry IV started promisingly, it quickly deteriorated because of a disagreement over events in Milan, where a reform group (the Patarines) struggled with traditional elements in the local church over succession to the bishop’s throne. The pope sided with the reformers, and Henry and his advisers supported the rival candidate for the bishop’s office in this important city. The involvement of Henry and his advisers in the affairs of the church of Milan brought papal condemnation and excommunication to the advisers. Henry’s association with the excommunicated advisers and his continued intervention increased tensions with Rome. His disobedience as much as his insistence on the right of lay investiture, which was not formally condemned until 1078, brought about a break with Gregory by the end of 1075.
Beyond the matter of lay investiture and the civil war brewing in Germany, Gregory and Henry were at odds over the nature of authority in the church—Henry claimed power over the activities of the church as the divinely appointed vice-regent of Christ, and Gregory presented himself as heir to the commission over all souls given by Christ to St. Peter (Matthew 16:18–19). On a more practical level, the controversy raised questions concerning the king’s authority over the church in his realm, the limits of church law, and the papal coronation of emperors.
In a letter of late 1075, after the impasse over Milan, Gregory chastised Henry for appointing bishops in Italy and for other failures, and the papal legate bearing the letter may have threatened Henry with excommunication. In response, Henry denounced Gregory as a false monk and demanded that he abdicate, and the imperial bishops renounced their obedience to the pope. At the Lenten synod in 1076, Gregory declared Henry excommunicated and deposed, and he released Henry’s subjects from their vows of loyalty. Gregory’s actions emboldened the opposition to Henry among the nobility, which agreed to meet, with Gregory in attendance, to decide Henry’s fate. In one of the most dramatic events of the Middle Ages, Henry journeyed to meet Gregory at Canossa in the winter of 1077 and, barefoot in the snow, sought forgiveness as a penitent sinner from the pope. Gregory had no choice but to lift the ban of excommunication and restore his rival to the church. Once absolved, Henry was able to reestablish himself in Germany and defeat the rebellion. Yet he continued to oppose Gregory, who excommunicated the king again in 1080 to little avail. Now secure in Germany, Henry invaded Italy, drove Gregory from Rome, and replaced him with Guibert of Ravenna, the antipope Clement III. Apparently defeated by Henry, Gregory died in exile—because, as Gregory said, he “loved justice and hated iniquity”—but the ideals he espoused, as well as the controversy he engendered, continued into the next century.
Gregory VII, though defending the independence of the church, was in fact tolerant of royal appointments that were free from simony. Pope Urban II (reigned 1088–99) was equally inconsistent, though in other ways he was a reformer. Upon his accession as pope, Paschal II (reigned 1099–1118) immediately condemned lay investiture, thus precipitating the crisis in England between Anselm (1033/34–1109), archbishop of Canterbury, and King Henry I (1069–1135). This and a similar crisis in France were settled by a compromise. Election (by the cathedral chapter) was to be free and lay investiture was waived, but homage before the bestowal of the fief was allowed. Meanwhile, Paschal—at odds with the German king Henry V (1086–1125), who demanded imperial coronation—suddenly offered to renounce all church property granted by the king if lay investiture were also abandoned. Henry accepted, but the bishops refused the terms; thereupon the king seized the pope, who agreed to lay investiture under duress. By this time, however, a large majority of bishops were Gregorians, and the pope was persuaded to retract.
Eleven years later Pope Calixtus II (reigned 1119–24) accepted the Concordat of Worms (1122), according to which free election by ecclesiastics was to be followed by investiture (without staff and ring, which were granted by the church) and homage to the king. This agreement ended a strife of 50 years, during which pamphleteers on both sides had revived every kind of claim to supremacy and God-given authority. Although formally a compromise, the settlement was in effect a victory for the monarch, for he could usually control the election. Nevertheless, the war of ideologies had exposed the weakness of the emperor, who in the last resort had to admit the spiritual authority of the pope over all Christians. The Crusades
The increased authority of the papacy and the relative decline in the power of the emperor became clear in the unforeseen emergence of the Crusades as a major preoccupation of Europe. Gregory VII hoped to lead an army to defend Eastern Christians after their disastrous defeat by the Seljuq Turks at Manzikert (present Malazgirt, Turkey) in 1071. Faced with the loss of Asia Minor and the continued expansion of the Turks, the Byzantine emperor Alexius I Comnenus (1057–1118) appealed for help to Pope Urban II in 1095. Urban’s celebrated call to the Crusade at Clermont (France) in 1095 was unexpectedly effective, placing him at the head of a large army of volunteers motivated by religious zeal and other more-mundane concerns. Although the capture of Jerusalem (1099) and the establishment of a Latin kingdom in Palestine were offset by disasters and quarrels, the papacy gained greatly in prestige and strengthened its position in relation to the emperor and Germany, which avoided participation in this first of many Crusades because of the ongoing Investiture Controversy. For more than two centuries, the Crusades remained a powerful movement headed by the pope. Numerous Crusades were waged in the Holy Land, and the Crusading ideal was applied to military and religious campaigns in Spain and eastern Europe. Later popes launched Crusades against heretics and opponents of papal authority and sanctioned the emergence of military orders. The Crusades thus reflected the widespread devotion to the church and to its leader, the pope. The papacy at its height: the 12th and 13th centuries
Gregory VII has often been portrayed as an innovator who lacked both authentic predecessors and authentic successors. It must be affirmed nonetheless that the later history of the papacy, modern as well as medieval, was shaped by what he and his followers did, and the continuing disabilities of the medieval papacy were largely the result of what they left undone. The hierarchical and sacerdotal structure of the late medieval and modern church owes much to the 11th-century reformers, though there had been earlier steps in its development. Throughout the 12th and 13th centuries, the papacy assumed a greater role in the direction of both church and society. The popes continued to exert their traditional authority over matters of doctrine and faith and presided over councils that ordered religious life and practice. The papal court became the court of last appeal, and the assertion of papal jurisdiction even into secular matters “by reason of sin” (ratio peccati) greatly expanded papal authority and sometimes led to conflicts with secular powers. The dispute over authority in the church, first evident in the Investiture Controversy, emerged repeatedly throughout the 12th and 13th centuries. The failure to resolve the matter of succession to the papal throne led to schisms that sometimes worsened imperial and papal relations. Impatience with the pace and the nature of reform also caused problems and contributed to the spread of heresy.
Much of the drama of papal history in this period derived from conflicts between popes and secular rulers in the empire, as well as in France and England. As noted above, contested papal elections led to schism and to church-state controversy in the 12th century and afterward. The election of 1159, for example, brought about a prolonged schism during which the emperor Frederick Barbarossa (c. 1123–90) promoted a series of antipopes who he hoped would be supportive of his policies. Frederick had previously run afoul of Pope Adrian IV (reigned 1154–59), who seemingly asserted that the emperor received his title as a beneficium (benefice), which would have entailed that the emperor was the pope’s vassal. Although not as serious as the Investiture Controversy, Frederick and Adrian’s dispute over beneficia in the incident at Besançon raised the question of who was the ultimate authority in Western Christendom and increased tensions between the emperor and the pope; the strong reaction of the emperor and lack of support for the pope in the German church forced Adrian to deny that he meant to imply the emperor was his vassal. Later popes also intervened in the affairs of kings and emperors. Innocent III became involved in the controversy in England between the nobles and King John (1167–1216), prohibited the divorce of the king of France, and played an active role in the politics of the empire. The popes of the 13th century pursued a vendetta against the Hohenstaufen dynasty that contributed to the breakdown of imperial authority in Germany and Italy.