George Ebedjesu Khayyath, Chaldean archbishop of Amid (Diyarbakir), in this volume explores the literary testimonies of writers in Syriac and Arabic from the Church of the East on the question of the primacy of the Roman pontiff. The notes contain a great number of source texts in Syriac and Arabic (which are translated in the text itself) along with several philological observations. Several chapters in appendices deal with the history of the Chaldean church and its use of Syriac. An index of names and subjects concludes the work. This study will be of interest to readers concerned with the interactions of the churches in the east, but also to students and scholars generally interested in the literature of the Church of the East.