Abstract
Among the most intriguing aspects of late Byzantine intellectual and religious history is the still poorly understood phenomenon of Greek theologians who renounced the schism between their native Church and the Church of Rome and advocated reunion with the latter. The unionist movement reached its high point in the Council of Florence and its declaration of union between the Latin and Greek Churches in 1439. Although the unionists have typically been dismissed as “Latin-minded” crypto-Catholics, lacking authentic Byzantine identity, who merely parroted back Western theology, I argue that unionists such as John Plousiadenos took a unique approach in advocating for Rome that reflected precisely their subjective identity as Byzantine Christians. This approach recognized the Roman Church as true because of its power and might in comparison with the weakness of the Byzantine Empire. Through a particular reading of ecclesiastical history, Plousiadenos and other unionists identified the Roman See with prophetic power capable of overcoming earthly kings and disturbing terrestrial kingdoms. For Plousiadenos, as well as other unionists who influenced him, the recent conquest of Constantinople by the Ottoman Turks stood as a warning to the rest of the Greek Christian world about the real-life consequences of rejecting Roman authority. Hence, for unionists in Plousiadenos’s vein, the earthly power of the Roman Church was a compelling proof of its theological claims.