The Crusades: The Authoritative History of the War for the Holy Land

by Thomas Asbridge

During the second half of the eleventh century, Latin Christianity began to edge ever closer towards the acceptance of holy war. In the early stages of the Reform movement, the papacy began to perceive the need for a military arm with which to reinforce its agenda and manifest its will. This prompted a succession of popes to experiment with the sponsoring of warfare, calling upon Christian supporters to defend the Church in return for vaguely expressed forms of spiritual reward. It was under the forceful guidance of Pope Gregory VII that the doctrine and application of sacred violence jumped ahead. Intent upon recruiting a papal army that owed its allegiance to Rome, he set about reinterpreting Christian tradition. For centuries theologians had characterised the internal, spiritual battle that devoted Christians waged against sin as the ‘warfare of Christ’, and monks were sometimes described as the ‘soldiers of Christ’. Gregory twisted this idea to suit his purpose, proclaiming that all lay society had one overriding obligation: to defend the Latin Church as ‘soldiers of Christ’ through actual physical warfare.