Had the subject of this book not left such a wealth of material in the day-to-day entries in his diaries and in the vast volume of his personal and other correspondence, the book could not have been written. Many other sources have of course been consulted. My first acknowledgment, however, must be to Mackenzie King himself, for his own contribution has been greater than anyone else's. My apologies to him if in a few places I have revealed more than he would have of incidents in his personal life, and have thereby invaded the privacy which he always took such pains to safeguard.
The idea of writing such a book as this grew out of circumstances which are described in the prologue. Dr. R. MacGregor Dawson, whose political biography of Mackenzie King was published in 1958, suggested that an extensive memorandum which I had prepared for him might be the basis for a separate volume. Later, Dr. Frank H. Underhill, as well as Walter B. Herbert of the Canada Foundation, encouraged me to think that the draft might be developed into a useful book. Their recommendation to Dr. John E. Robbins of the Social Science Research Council of Canada resulted in the Council's authorizing generous financial assistance which made possible the preparation of the manuscript. To these friends, and to the Research Council, I am deeply grateful, as I am to John M. Gray, president of the Macmillan Company of Canada, whose friendly interest in the work at every stage has done so much to stimulate action and overcome discouragements. I offer my