Religion and diplomacy: the role of the Disputatio in Byzantine-Latin relations after 1204

This study considers the development and evolution of Byzantine diplomacy through a crucial and previously overlooked period of the empire’s history. Current scholarship has neglected the analysis of Byzantine diplomacy from 1204, when the capital of Constantinople was seized by the Fourth Crusade, to 1261, when the city was returned to Byzantine control. During these years the institutions of the Byzantine state were preserved at Nicaea, which continued the complex relationship between Greeks and Latins and adapted the tested methods of diplomacy to meet new challenges. Of central concern is the frequency of church-union negotiation, or disputatio, during the period in question. Attempts to heal the schism of the Eastern and Western Churches were a frequently used tool of Byzantine diplomacy even before 1204, but the sources, problems and implications surrounding this aspect of foreign relations, although taken up by those pursuing theological analysis, have been neglected by historians. The emperors in Nicaea repeatedly opened talks with the papacy to end the schism before 1261, most notably in 1234, a meeting which carried profound implications for Byzantine foreign policy. By placing the disputatio in the context of Byzantine-Latin relations after 1204, we gain a more complete understanding of Byzantine diplomacy.