The thesis deals with representations of the First Crusade in texts and images in the twelfth century. The main focus is on the most dramatic episode of the expedition, the Battle of Antioch, fought on June 28 ^th, 1098, in which crusaders emerged victorious despite tremendous odds. Rather than attempting to uncover what had actually happened during the battle, the thesis analyzes descriptions of the engagement in order to understand the patterns of thought of contemporaries and near-contemporaries of the First Crusade. It pays particular attention to the narratives of the miracle of the intervention of celestial troops on the battlefield on behalf of crusaders. Instead of attempting to reconcile the different sources, which has been the common approach in crusader studies, it focuses on their idiosyncrasies. Examining significant variations between the accounts of the miracle, it attempts to establish the existence of conflicting interpretations of the First Crusade. In doing so, it also challenges the invisible wall that appears to separate crusader studies from research done on intellectual trends of the twelfth century. The thesis considers not only first-hand chronicles, but also a number of underprivileged sources: second-hand narratives, a vernacular Chanson d'Antioche and visual representations. Among the latter, it concentrates on the representation of the Battle of Antioch in the program of mural paintings in the church of Poncé. The thesis inscribes the narratives of celestial intervention in a broader European and Mediterranean context, investigating similar accounts found in Greco-Roman, Byzantine and Islamic traditions. It pays particular attention to comparisons made by medieval thinkers between crusaders and Maccabees, who were also reported to have profited from divine aid on the battlefield. Finally, it examines the treatment of the problem of reliability of eyewitnesses, particularly of those of miracles, in crusading texts. The sources of the First Crusade reveal their authors' anxiety regarding such subjects as the boundary between the sacred and the profane; the correct uses of the Old Testament to interpret the present; and, more specifically, the real significance of the events unfolding in the Holy Land.