God's War: A New History of the Crusades by Christopher Tyerman

Acknowledgements
    This book has taken longer than even the most sluggish crusade to prepare and complete. I must record my thanks and gratitude to the Trustees of the Leverhulme Trust for the award of a Research Fellowship for the year 1998–9, which allowed me to begin to marshal evidence and ideas for this project. My agent Jonathan Lloyd has proved a tactful and potent warrior in my interests. The invitation to write this sort of book came from Simon Winder, who could not have imagined how long, in many senses, it would turn out to be. His patience and encouragement have been wonderfully sustaining. Indirectly, I have been thinking, working, teaching and writing towards this book for thirty years. Inevitably the debts to friends, colleagues, pupils and other scholars are legion and irredeemable. In particular, I should like to register my obligation for discussion, ideas, criticism and opportunities to air views to Malcolm Barber, Toby Barnard, Peter Biller, Jessalynin Bird, the late Lionel Butler, Jeremy Catto, Eric Christiansen, Gary Dickson, Barrie Dobson, Jean Dunbabin, Peter Edbury, Geoffrey Ellis, L.S. Ettre, the late Richard Fletcher, John Gillingham, Timothy Guard, Bernard Hamilton, Ruth Harris, Catherine Holmes, Norman Housley, Colin Imber, Kurt Villads Jensen, Jeremy Johns, Andrew Jotischky, Maurice Keen, Anthony Luttrell, Simon Lloyd, Jose-Juan Lopez-Portillo, Dominic Luckett, John Maddicott, Hans Mayer, James Morwood, Alan Murray, Sandy Murray, Torben Nielsen, the Oxford University Department of Continuing Education Crusades class of the summer of 2003, David Parrott, Jonathan Phillips, the late John Prestwich, Jonathan Riley-Smith, Miri Rubin, Jonathan Shepard and Mark Whittow. The intellectual vibrancy of my colleagues and pupils in Hertford College and New College provide the most stimulating of creative environments. The Principal and Fellows of Hertford gave me academic shelter for manylocust years. Toby Barnard and Peter Biller have long provided personal support and intellectual stimulus with rare companionability. The responsibility for introducing me to the crusades rests with the improbable quintet of the late Ralph Bathurst, David Parry, Eric Christiansen, Maurice Keen and the late Lionel Butler, alike in little except inspiration and civility. I alone can be held accountable for the errors that stubbornly remain like mouse hairs in medieval bread. Simon Winder, editor nonpareil, and his team at Penguin UK have proved a revelation of amenable, intelligent and efficient publishing. I am grateful to those who have pointed out errata in the First Edition, in particular Paul Cobb and Eric Christiansen. For tolerating the distraction of what must at times have seemed another sibling, the book is dedicated to those most healthily but supportively sceptical of the virtues and merits of this work and its author, Elizabeth, Edward and Thomas, with love.
    CJT
Oxford
15 June 2007

Preface
    ‘The Lord is a man of war.’ (Exodus 15:3)
    Violence, approved by society and supported by religion, has proved a commonplace of civilized communities. What are now known as the crusades represent one manifestation of this phenomenon, distinctive to western European culture over 500 years from the late eleventh century of the Christian Era. The crusades were wars justified by faith conducted against real or imagined enemies defined by religious and political elites as perceived threats to the Christian faithful. The religious beliefs crucial to such warfare placed enormous significance on imagined awesome but reassuring supernatural forces of overwhelming power and proximity that were nevertheless expressed in hard concrete physical acts: prayer, penance, giving alms, attending church, pilgrimage, violence. Crusading reflected a social mentality grounded in war as a central force of protection, arbitration, social discipline, political expression and material gain. The crusades confirmed a communal identity comprising