This work in its inception was inspired by Professor Albert Ten Eyck Olmstead, Oriental Institute Professor of Oriental History in the University of Chicago. From what seemed at times an inexhaustible store of knowledge, he has often pieced together the scattered threads of historical data into a perfect whole. From his unrivaled ability to see each isolated fact in its relationship to the entire picture he has given to this study a perspective it could never otherwise have achieved. From his unpublished notes and manuscripts, and, more than these, from his discussions, criticisms, and suggestions at every stage of the progress, I have obtained more than words can say. From him I have secured encouragement in hours of perplexity; his aid, given unstintingly, has enormously lightened my labors.
Professor Arno Poebel and Professor F. W. Geers have often confided to me, as student and friend, their opinions on historical questions and their improved translations of historical documents. Professor Geers and Dr. I. J. Gelb have done me the great service of reading the manuscript and offering their suggestions. The unwavering enthusiasm and vitality of Professor M. Sprengling have often heartened me in moments of despair. Other members of the Oriental Institute staff and of the Department of Oriental Languages and Literatures have been no less kind. To the Oriental Institute and its director, Professor James H. Breasted, as well as to the University of
