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!