This third volume of Larry Clark's monumental work of publishing the complete corpus of Old Turkic Manichaean texts features the Ecclesiastical Texts, i.e., those that reflect the affairs or activities of the Manichaean church and its membership during the period from the second half of the 8th century to the first half of the 11th century when it enjoyed the protection and patronage of portions of the Uygur elites, both in the northern Steppe Empire and in the western Tien Shan realm. Included here are benedictions on sacerdotal and political leaders, colophons identifying the sponsorship and occasions of book production, historical narratives of the adoption and defense of Manichaeism by heroic Uygur rulers, letters to and from religious leaders, monastic documents on the history and operation of manistans and reporting their demise as the Uygur elites switched their loyalty to Buddhism, and various fragments of ephemera. It is a remarkable achievement of linguistic and historical detective work, solving a number of longstanding problems and shedding new light on Manichaean community life in medieval Central Asia.