Gregory IX and the Greek East *1

This chapter examines Pope Gregory IX’s involvement in the Greek East, which revolved around three interconnected issues: crusade, Church Union, and heresy. Gregory used both force and negotiations in pursuit of the dual objectives of protecting Latin possessions in the area and effecting papal control over the Eastern Churches. He actively deployed the crusade to buttress the Latin conquest of Byzantium, while he was also involved in Greek-Latin ecclesiastical contacts in Greece, Cyprus, Syria, and southern Italy. In a striking – if short-lived – departure from precedent, Gregory explicitly accused the Greek Church of heresy. At the same time, his envoys’ (eventually unsuccessful) negotiations with the authorities of Nicaea were an implicit recognition of the government and hierarchy established there as continuators of Byzantium.