While the 18th-century Scottish philosopher and historian David Hume thought the Crusades ‘the most signal and most durable monument of human folly that has yet appeared in any age or nation’, he admitted they ‘engrossed the attention of Europe and have ever since engrossed the curiosity of mankind’. The reasons for this are not hard to find. The twin themes of judgement on past violence and fascination with its causes have ensured the survival of the Crusades as more than an inert subject for antiquarians. Since Pope Urban II (1088–99) in 1095 answered a call for military help from the Byzantine emperor Alexius I Comnenus (1081–1118), by summoning a vast army to fight in the name of God to liberate eastern Christianity and recover the Holy City of Jerusalem, there have been few periods when the consequences of this act have not gripped minds and imaginations, primarily in western society but increasingly, since the 19th century, among communities that have seen themselves as heirs to the victims of this form of religious violence. With the history of the Crusades, modern interest is compounded by spurious topicality and inescapable familiarity. Ideological warfare and the pathology of acceptable communal violence are embedded in the historical experience of civilization. Justification for war and killing for a noble cause never cease to find modern manifestations. The Crusades present a phenomenon so dramatic and extreme in aspiration and execution and yet so rebarbative to modern sensibilities, that they cannot fail to move both as a story and as an expression of a society remote in time and attitudes yet apparently so abundantly recognizable. Spread over five hundred years and across three continents, the Crusades may not have defined medieval Christian Europe, yet they provide a most extraordinary feature that retains the power to excite, appal, and disturb. They remain one of the great subjects of European history. What follows is an attempt to explain why.
The phenomenon of violence justified by religious faith has ebbed and flowed, sometimes nearing the centre, sometimes retreating to the margins of historical and contemporary consciousness. When I was asked to write this short introduction to the Crusades, holy war, Christian or otherwise, was not high on the public or political agenda. Now when I have finished, it is. So this work conforms to a pattern traced in what follows, of historical study relating to current events. My views on that relationship will, I hope, become clear enough. What remain hidden except to the lynx-eyed are the debts to many other scholars, colleagues, and friends from whom I have learnt so much and should have remembered so much more. They must forgive a collective thanks. The faults in this libellusare mine not theirs. The dedication is a very small recompense for incalculable munificence of advice, support, and friendship over so many years, in dark days as well as bright evenings of exhausting but inexhaustible hospitality.
C. J. T.
22 May 2005