Peccatis Merentibus ? The Theological Explanation for Muslim Expansion in Papal Correspondence, from Martin I to Urban II

This essay examines the evolution of the theological interpretation of Muslim expansion in papal correspondence from the pontificate of Martin I (649–55) to that of Urban II (1088–99). It identifies the historical moment and the conditions that led the Apostolic See to adopt the interpretation that Islamic conquests were consequences for the sins of the Christian people. Through a systematic analysis of papal correspondence, the study demonstrates that this explanation was consciously avoided until the tenth century to preserve the authority of the papacy. Only during the eleventh century, with the end of direct threats to Rome and a shift in the geopolitical balance, this interpretation begins to enter papal rhetoric. Papal political theology was shaped by historical contingencies and institutional circumstances, evolving in response to changing geopolitical and religious contexts.