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

by Thomas Asbridge

At first sight, Christianity does appear to be a pacifistic faith. The New Testament Gospels record many occasions when Jesus seemed to reject or prohibit violence: from his warning that he who lived by violence would die by violence, to the Sermon on the Mount’s exhortation to turn the other cheek in response to a blow. The Old Testament also appears to offer clear guidance on the question of violence, with the Mosaic Commandment: ‘Thou shall not kill.’ In the course of the first millennium CE, however, Christian theologians pondering the union between their faith and the military empire of Rome began to question whether scripture really did offer such a decisive condemnation of warfare. The Old Testament certainly seemed equivocal, because as a history of the Hebrews’ desperate struggle for survival, it described a series of holy wars sanctioned by God. This suggested that, under the right circumstances, even vengeful or aggressive warfare might be permissible; and in the New Testament, Jesus had said that he came to bring not peace but a sword, and had used a whip of cords to beat moneylenders out of the Temple.