The conflict between Gregory VII and Henry IV (1056–1106) over lay investiture was a culmination of developments in Italy that had their origins in the last years of the pontificate of Leo IX. At the Roman synod of 1075, Gregory signaled his determination to bring an end to the practice of lay investiture. There could be no doubt that this policy would have its most drastic impact on Germany and northern Italy, where the remains of the Ottonian system constituted important vestiges of imperial control. Henry IV and his counselors realized these implications and replied at the synod of Worms in 1076. Henry employed a frontal attack on Gregory, challenging the legitimacy of his election. Gregory’s response was equally provocative: he excommunicated Henry, which released his subjects from their allegiance. This calculated political response aimed at undermining Henry’s position with the German aristocracy. Faced with rebellion, Henry made his celebrated trek across the Alps to meet the pope before he could come to Germany. Pope and emperor met at Matilda’s castle in Canossa. There, amid the snows of winter, Henry stood for three days as a penitent until the pope received and absolved him. Henry’s action at Canossa saved him temporarily, but he remained in jeopardy. When the conflict resumed in 1080, Gregory again excommunicated Henry, who proceeded to gather his supporters. A synod at Brixen under Henry’s control elected Guibert of Ravenna as pope under the name Clement III (elected antipope in 1080; enthroned antipope in 1084–1100). Henry led his army into Italy and laid siege to Rome. Gregory turned for assistance to Robert Guiscard and the Normans, who drove Clement and Henry from Rome but also sacked the city (1084). Gregory went south with Guiscard and the Normans, where he died in Salerno in 1085.
Gregory’s defeat did nothing to strengthen the position of the empire in northern Italy, while it drove the papacy closer to the Normans. The election of Abbot Desiderius of Montecassino as Pope Victor III (1086–87) illustrates this change, since Desiderius had long functioned as an intermediary between the papacy and the Normans. The election of Urban II (1088–99), formerly a monk of Cluny in Burgundy and a strong supporter of Gregory’s policy, showed the continued strength of the Roman Curia’s resolve and at the same time initiated closer ties to the Capetian kings of France as a counterweight to the empire and an alternative to the Normans. Urban was also effective in gaining support for reform among the cities of northern Italy. Yet his most dramatic endeavour was his summons of the Crusade" class="md-crosslink">First Crusade at Clermont in 1095, presaged by his earlier meeting with Byzantine envoys in Italy. Urban’s commitment to the Crusade proceeded from his desire to heal the schism between the Eastern and Western churches, to extend the papal reform program to the Eastern churches, and to forge a new alliance within Christendom against Islam, its foremost external enemy. The Crusade offered new opportunities for the maritime cities of northern Italy, which for some time had been opposing Muslim power in Sardinia, Corsica, and Sicily. Urban also worked closely with Roger I, count of Sicily, to reestablish the Latin church on the island, but he came into conflict with him over the degree of direct papal control to be exercised there. The apostolic legation that he granted to Roger and his son limited direct papal intervention in the ecclesiastical affairs of the island and thereby joined the reconstruction of the church to the interests of the Norman monarchy (see below). At his death in 1099, Urban had greatly enhanced the prestige of the papacy, yet the conflict with the empire remained unresolved.
The settlement of the investiture struggle that finally emerged under Popes Paschal II (1099–1118) and Calixtus II (1119–24) had a far-reaching impact on the church and on civil society. The settlement represented a compromise between the reformist church and the empire. The agreement reached between Paschal II and King Henry I of England, which limited the role of the king in the appointment of bishops, marked the direction for the eventual solution reached by Calixtus II and Henry V (1106–25) in the Concordat of Worms in 1122. Thenceforward, the emperor was denied the right to invest prelates with the spiritual symbols of their offices; however, as their temporal overlord he retained certain rights (the ones for Germany differing substantially from those for Burgundy and Italy). An earlier attempt at settlement had proposed a near-total severance of the ties between the bishops and the monarchy and thus an end to the Ottonian system. While such an arrangement would have satisfied every aim of the reformers, it would have plunged the empire into chaos. The bishops, well aware of their role as linchpins, objected strongly to such a radical solution, and the plan foundered. But the compromise at Worms was also fraught with danger for the empire. The reformers gained much more than the actual agreement granted. The chief beneficiary was the papacy, which succeeded in freeing itself from imperial restraints. In the temporal sphere, however, and largely by accident, northern and central Italy also faced a new situation as a result of this settlement. The rise of communes
During the 12th century, communes, or city-states, developed throughout central and northern Italy. After early beginnings in cities such as Pisa and Genoa, virtually every episcopal city in the north formed a communal government prior to 1140. The origins and developments of communes are complex, and attempts to explain them in simple terms are doomed to failure. The emphasis of 19th-century liberal historians on communal revolts against ecclesiastical repression as well as the later Marxist focus on class conflict in the development of the communes have proved too narrow. They have failed to recognize both the many different causes of violence in the communes and the diversities within the communal movement. Violence resulted from such diverse factors as the conflicting interests of ecclesiastical institutions, the complex ties of loyalty that bound men to one another and to the institutions of their society, and shifts in the distribution of power.
The Investiture Controversy focused the efforts of the higher clergy on consolidating their rights against infringement not merely by the lay aristocracy but also by ecclesiastical competitors. Examples of conflict from various places and periods show how relationships changed dramatically, often within a short period. At Brescia, for example, the bishops, who contested the abbots of Leno for control of the church of Gambara, drew support from a faction of the milites, the landed aristocracy, as well as from the popolo, which was composed of professional people, craftsmen, and merchants. Elsewhere, local circumstances dictated other alliances. During the period in which the cities were expanding their power into the contado (the region surrounding the city), elements drawn from town and countryside continually struggled for control of the commune. Alliances shifted depending on the success or failure of these efforts. At Lucca the bishop and the commune were jointly concerned about the claims of the Abbey of Fucecchio because of its ties to neighbouring Pisa. But the efforts of bishops to establish their rights in the contado could also provoke conflict with the commune. Much depended on the makeup of the commune, which varied widely not only from city to city but also from period to period. The relative influence of urban merchants or rural landholders depended on the size of each group within a particular community. Where one group was small, it allied itself with others. The quest for power led to shifting and, at times, strange alliances; for example, at Brescia in the early 13th century, one faction of local magnates drew support from heretics. Even when the commune brought together various factions in sworn associations, it still faced not only the problem of its enemies in the city and countryside but also that of the fragile nature of the coalition on which it rested. Communes created elaborate systems of checks on power that aimed to prevent dominance by any single faction. Term limits were imposed to force changes in the ruling councils. The consuls, so named from Roman precedent, similarly faced limits on their power.