While there is a general agreement among the writers as to principles, the greatest freedom as to treatment is allowed to writers in this series. The volumes, for example, are not of the same length. Volume II, which deals with the formative period of the Church, is, not unnaturally, longer in proportion than the others. To Volume VI, which deals with the Reformation, has been allotted a similar extension. The authors, again, use their own discretion in such matters as footnotes and lists of authorities. But the aim of the series, which each writer sets before him, is to tell, clearly and accurately, the story of the Church, as a divine institution with a continuous life. W. H. Hutton PREFACE The late appearance of this volume of the series needs some explanation. Portions of the book have been written at intervals; but it is only the enforced idleness of a long convalescence after illness which has given me the requisite leisure to finish it. I have tried to avoid overloading my pages with details of political history; but in no period is it so easy to miss the whole lesson of events by an attempt to isolate the special influences which affected the organised society of the Church. The interpretation which I have adopted of the important events at Canossa is not, of course, universally accepted; but the fact that it has seldom found expression in any English work may serve as my excuse. The Editor of the series, The Rev. W. H. Hutton, has laid me under a deep obligation, first, by his long forbearance, and more lately, by his frequent and careful suggestions over the whole book. It is dangerous for laymen to meddle with questions of technical theology. I trust that, guided by his expert hand, I have not fallen into any recognisable heresy! Mears Ashby, _October_, 1910. CONTENTS INTRODUCTORY CHAPTER I THE BEGINNINGS OF CHURCH REFORM CHAPTER II GREGORY VII AND LAY INVESTITURE CHAPTER III THE END OF THE QUARREL CHAPTER IV THE SECULAR CLERGY CHAPTER V CANONS AND MONKS CHAPTER VI ST. BERNARD CHAPTER VII THE SCHOOLMEN AND THEOLOGY CHAPTER VIII GUELF AND GHIBELLINE (I) CHAPTER IX INNOCENT III CHAPTER X THE PAPAL POWER IN THE CHURCH CHAPTER XI DOCTRINE AND DISCIPLINE OF THE CHURCH CHAPTER XII HERESIES CHAPTER XIII THE MENDICANT ORDERS CHAPTER XIV THE CHURCH AND THE HEATHEN CHAPTER XV GUELF AND GHIBELLINE (II) CHAPTER XVI THE FALL OF THE EMPIRE AND OF THE PAPACY CHAPTER XVII THE CHURCHES OF THE EAST The Church and the Empire Introductory [Sidenote: Political thought in Middle Ages.]