IN January 1937 Mme. Henri Pirenne and M. Jacques Pirenne brought to my notice the manuscript of a posthumous work of my late master, asking me to assist in its revision with a view to its publication. The text with which I had to deal was complete, but it was a first draft. It had, however, been slightly revised, as regards its form only, by M. Jacques Pirenne.
Before all, Henri Pirenne's ideas had to be loyally respected. I have therefore refrained from making any alterations or suppressions or additions which would in any way have modified the thesis expounded by this eminent historian, even though there were passages which seemed to me debatable. In these pages, therefore, the reader will find a work which is strictly personal to Henri Pirenne.
At the same time, however, I had to verify the material accuracy of a certain number of facts, dates, and quotations. The footnotes and bibliographical references indispensable in a work of this character were very often given only in the germ; these I felt I could revise and develop in conformity with the requirements of contemporary scholarship. In some cases I have even thought it desirable to cite one or more additional texts in support of the views expressed by my eminent master.
For more than twelve years it was my great privilege to work under the guidance and with the assistance of Henri Pirenne: and I think I may say that I was fully conversant with the ideas and the theories which he held as regards the subject of the present volume, in respect of which he had already undertaken a great deal of preparatory work. Destiny unhappily decreed that he was not to offer to the public a completed work, fresh from his own pen. It goes without saying that I have not entertained the presumptuous ambition of giving to the work those finishing touches of which he alone would have been capable, and to which he would have brought an objective care, a conscientious scholarship