God's War: A New History of the Crusades

In recruiting allies or raising their own troops, later eleventh-century popes were fully aware of the theoretical implications as much as the political necessities. The moral standing of those who fought for the pope became a matter of acute concern. In 1053, Leo IX (1048–54) offered German troops who fought (unsuccessfully) under his personal command against the Norman bandit lords of southern Italy remission of penance and absolution of sins. In 1059, as a result of a major diplomatic revolution, these same Normans became papal vassals, with the obligation to fight for their new lord. Papal banners were granted the Norman invaders of Sicily (in 1060) and England (in 1066) and to Milanese street gangs, the Patarines, engaged in a violent and protracted struggle for the eradication of clerical abuses and control of the archbishopric of the city in the 1060s and 1070s. Holy war became part of the papal programme. The Patarine conflict was called a bellum Dei, a war of God, the fallen Patarine leader Erlembald (d. 1075), a martyr. The key testing ground of papal reform and power was in Germany, where any loosening of the link between church and state or challenge to imperial authority was fiercely opposed by Emperor Henry IV. From the late 1070s disagreements turned to war, the so-called wars of the Investiture Contest, although the issues were far broader than whether or not kings should invest bishops with ring and staff. To fight for papal interests, the most militant of the reforming popes, Gregory VII, even attempted to recruit knights from across Europe to form a papal army, a militia sancti Petri, a Militia of St Peter.

Gregory VII significantly developed the theory and practice of holy war and holy warriors. Although not given to citing Augustine of Hippo himself, his loyal henchman Bishop Anselm II of Lucca, in his Collectio canonum (i.e. Collection of canon law) of c.1083, brought together the Augustinian theories of just war in one contained, intelligible and coherent place for the first time, although its circulation was limited. Gregory, one of whose favourite scriptural quotations was ‘Cursed is he who keeps back his sword from bloodshed’ (Jeremiah 48:10), preferred a moral rather than legal approach. He identified two forms of occupation for arms-bearers, one secular, selfish and sinful, the other penitential, justified by legitimate rights, loyalty to a lord, protection of the vulnerable or defence of the church. Writing in the decade after Gregory’s death, a vigorous papalist propagandist, Bishop Bonizo of Sutri, in his Liber de Vita Christiana, identified those who, ‘for their salvation and the common good’, fought schismatics, heretics and excommunicates and protected the poor, orphans and widows, as members of an ‘ordo pugnatorum’, an order of warriors to rank in the social hierarchy, precisely the group implied by the Militia of St Peter and to whom Urban II sought to direct his appeal in 1095.²⁹ By the end of his stormy pontificate, Gregory VII offered all who fought for his cause, in whatever fashion, absolution of their sins and the prospect of eternal salvation. Provided their motivation was grounded on selflessness and faith not gain, such soldiers could combine penance and violence. In castigating his opponents and encouraging his followers Gregory extended his rhetoric, likening service in such a just war as an imitation of Christ’s sufferings against ‘those who are the enemies of the cross of Christ’.³⁰