The Fourth Crusade (1201-1204), launched to restore Jerusalem to Christian control, veered widely off course, finally landing at Constantinople which it conquered and sacked. The effects of the crusade were far-reaching during the Middle Ages and remain powerful even today, which explains the continued vibrancy of its historiography. This volume, based on studies presented at the Sixth Conference of the Society for the Study of the Crusades and the Latin East in Istanbul, Turkey in 2004, represents some of the best new research on this fascinating event. With the "Diversion Question" of the past centuries now largely settled, these studies focus on three aspects of current scholarship: evaluations of the event itself, investigations into the aftermath of the conquest of Constantinople in 1204, and analyses of the evolving perceptions and memories of the event in Europe and the Middle East. Together these essays help to place the Fourth Crusade within the larger context of medieval Mediterranean history as well as larger issues such as agency, accommodation, and memory that inform new aspects of modern historiography.