The appearance of another history of the early Church requires some explanation. As the progress of the Christian commonwealth for the first three hundred years has been recently described by British, German, and American writers of eminent ability, it may, perhaps, be thought that the subject is now exhausted. No competent judge will pronounce such an opinion. During the last quarter of a century, various questions relating to the ancient Church, which are almost, if not altogether, ignored in existing histories, have been earnestly discussed; whilst several documents, lately discovered, have thrown fresh light on its transactions. There are, besides, points of view, disclosing unexplored fields for thought, from which the ecclesiastical landscape has never yet been contemplated. The following work is an attempt to exhibit some of its features as seen from a new position.