The principal literary achievement of Peter of Callinicus, patriarch of Antioch from 581 to 591 is the rebuttal, directed against his co-religionist Damian, pope of Alexandria from 557/8 till 606/7. It has waited a long time for publication in a modern edition: the work survived not in its Greek original, but in Syriac translation, the theme is technical and complicated and its author belongs to a period and to a communion unfamiliar to most students of Christian life and thought in the patristic era.