One of the pleasures and privileges of scholarship is the opportunity to express one's gratitude to friends and colleagues upon the occasion of a publication. As with many scholarly first books, this present work had its genesis as a doctoral dissertation, and hence my first and most profound acknowledgment must be to Professor S. Harrison Thomson of the University of Colorado, whom I am honored to be able to describe as my mentor. Only my fellow "Old Thomsonians" can appreciate the common debt we owe to this great medievalist who was also a magni­ ficent teacher and counsellor. Presently in retirement, he continues to be our principal inspiration and model of scholarly distinction. I am also greatly indebted to another former mentor and now my senior colleague and chairman at the University of Denver, Professor Allen D. Breck, who, together with Deans Edward A. Lindell and Gerhard H. Mundinger, constantly encouraged and assisted my further progress and read the manuscript in its final stages, offering many valuable sugges­ tions as to style and substance. My university provided me with generous support in the form of research funds and clerical services; I am grateful to. those colleagues who made this assistance possible, as well as to friends at other institutions who shared their knowledge and frequently gave salutary advice.