제4차 십자군
The prominent medievalist Sir Steven Runciman wrote in 1954: "There was never a greater crime against humanity than the Fourth Crusade." The controversy that has surrounded the Fourth Crusade has led to diverging opinions in academia on whether its objective was indeed the capture of Constantinople. The traditional position, which holds that this was the case, was challenged by Donald E. Queller and Thomas F. Madden in their book "The Fourth Crusade" (1977).