God's War: A New History of the Crusades

This was much more than a theological spat. The power of the German kings relied heavily on control of the church, especially in Saxony. A revolt there in 1076 gave the most belligerent of the reforming popes, Gregory VII, an opportunity to put pressure on Henry IV to make concessions by publicly challenging his right to rule, claiming the pope possessed a plenitude of power that included the right to depose unsuitable monarchs, including emperors. The intransigent Henry IV was excommunicated in 1076 and again in 1080. Rival kings were put up by the papalist and anti-imperialist party in Germany. The ensuing war spilt over into Italy. In 1084 Henry IV invaded, captured Rome, installed his own anti-pope and forced Gregory VII to find refuge with the Norman conquerors of southern Italy. Over the subsequent decade, Henry’s anti-pope held sway in Rome, supported by repeated imperial forays south of the Alps. The background to the First Crusade lay in this conflict, as Urban II sought to use the mobilization of the expedition as a cover to reclaim the pope’s position in Italy and demonstrate his practical leadership of Christendom, independent of secular monarchs. The slogan of the papal reformers was ‘libertas ecclesiae’, ‘church freedom/liberty/rights’. This provided the central appeal of Urban II’s summons of 1095, when he called on the faithful to go to ‘liberate’ the churches of the east and Jerusalem. The crusade is impossible to understand outside of this context of more general church and papal reform. It was ironic that, at the very time they were asserting universalist claims, the reforming popes could never be entirely secure in Rome itself. Local nobles, deprived of control of the lucrative office of the papacy, German and pro-imperialist invaders and other Italian political rivals forced successive popes into temporary or near-permanent exile over the century following Gregory VII’s exile. It was only after he had launched the First Crusade in 1095–6 that Urban II was himself able to establish his residence in the Eternal City.

The Investiture Contest, only resolved by compromise in 1122, exposed some of the weaknesses in the material and ideological positions of both papacy and empire, as well as highlighting the limitations of centralized political authority more generally. The papacy was, with the English government of the time, one of the leaders in western Europe pioneering the development of written techniques of government – communicating with local agents, subordinates and representatives abroad by standardized letters; systematic, retrievable record keeping; the creation of a bureaucratic tradition. Yet, as was later famously remarked, the pope lacked legions, having to rely on secular protectors to secure papal independence and integrity. By contrast, the German emperor was politically the most powerful ruler in western Europe, wielding vast theoretical and potential power over territories that stretched from southern Denmark to central Italy. Yet these lands, based on the eastern portion of the old Carolingian empire (known from the ninth century as East Francia), were held together by networks of dynastic alliance, personal relations, tradition, ideology, convenience and brute force, not institutional routine. This made the building of political consensus, the basis to all effective authority, a full-time and precarious exercise for German rulers in the eleventh century. Since 962, the king of Germany could hope to be crowned by the pope as Roman emperor. Despite the Investiture Contest and continued tension thereafter, most kings succeeded in persuading popes to perform this highly symbolic and important ceremony. However, some did not. King Conrad III of Germany, commander of the Second Crusade (1145–9), was one of the few medieval German kings after Otto I not to be crowned emperor, although he nonetheless exercised many of the imperial prerogatives and gave himself some of the formal titles of an emperor. The lack of imperial title reduced a German king’s claims to jurisdiction in North Italy, one of the wealthiest regions of western Europe, which formed a significant and lasting element in imperial pretensions. However, Conrad’s power, like that of his predecessors, depended on his position in Germany.