This book is an investigation of the process by which large parts of Europe accepted the Christian faith between the fourth and the fourteenth centuries and some of the cultural consequences that flowed therefrom. It is therefore unfashionably ambitious in scope. Professional historians today are expected to know more and more about less and less, and to communicate their findings to other professional historians in those weird gatherings known as academic conferences. In consequence fewer and fewer people are going to list what they have to say. --- excerpt from book's Preface