So many times have I thought that this page would never be written, that it is with great relief that I can now begin to thank all the friends and people who have in one way or another given me assistance or inspiration. Because in a previous incarnation part of this book was my doctoral dissertation, my first debt of gratitude goes to the members of my doctoral committee in the then Department of Uralic and Altaic Studies at Indiana University: Christopher I. Beckwith — with whom I first discussed my idea — and Yuri Bregel, György Kara, and Elliot Sperling, who allowed me to pursue an interest that was at best tangential to the mainstream of the discipline. Lynn Struve was an exceptionally scrupulous and insightful external member. I must also thank Denis Sinor for encouraging me, while I was still a graduate student, to present papers at several conferences. I did much of the research that eventually went into this book at Cambridge University, where I was a Research Fellow in the Mongolia Studies Unit (1989–92); my sincere thanks to Caroline Humphrey and to the staff of the Mongolia Studies Unit and the Faculty of Oriental Studies for having given me valuable and muchappreciated support.
The dissertation being written, I had no intention of continuing my research in ancient Chinese history. If I have persevered, the merit belongs to Michael Loewe and Edward Shaughnessy. In different ways, they are among the best scholars I have ever worked with. Loewe's valuable works were the first that I read in this field and also the last, given the inexhaustible pace of his scholarship. Although not an Inner Asian specialist, Loewe (in collaboration with Hulsewé) has done more to enlighten our understanding of the ancient relations between China and Central Asia than any other scholar, including Pelliot and Chavannes.
Loewe and Shaughnessy's influence on this book has also been essential in a very direct way. I was thrilled when they asked me to contribute a