Examines the role of the Christian Church in the formation of Western civilization, tracing institutional developments as well as the religious and intellectual life during the period 400-1500 A.D.A history of the medieval Church that combines both source material and narrative. Within each discussion, the author refers the reader to pertinent documentary readings, included for reference and analysis. Most of these documents have been freshly translated by the author, and many of their passages are little known though highly characteristic of the period. Significant biographical details and anecdotes are interspersed throughout the essay.