“But hasn't that been done before?” was the question put to me by a colleague as we sat at dinner after the last session for the day at the International Congress of Medieval Studies in Kalamazoo, Michigan, a few years ago. Like her, those familiar with the Albigensian Crusade will wonder how this book adds to what anglophone scholars such as Walter M. Wakefield, Joseph Strayer, Jonathan Sumption and Michael Costen, and multi-volume accounts in French like Michel Roquebert's, have said in the last thirty-five years. That does not even count the contributions of popular authors like Zoé Oldenbourg, Stephen O'Shea, other novelists and rapidly growing Internet sites on the Cathars and the Crusade. The Crusade is certainly not unexplored territory, which is what my dinner companion really meant.

Her question was a valid one, and she listened patiently as I explained the necessity of one more book on the Albigensian Crusade. The crusades to the Middle East have always had their long-view adherents, like Hans Eberhard Meyer and Jonathan Riley-Smith. They have also been the subject of multivolume projects like those edited by Kenneth Setton. These long looks remain essential to understanding how the crusading concept began and evolved, the outline of political and military events, the individuals involved, and to tracing the development of East–West relationships over two hundred years.