Events of the past decade have once again placed the Korean peninsula in the position of a buffer state where the wars of greater powers are focused. Historians will recall that Korea has had this role thrust upon her many times before. In recent times the peninsula was the battleground for theS ino-J apanese War of 1894-1895 while the opening battle of the Russo-J apanese War of 1904-1905, a naval action, took place off the present port of Inch 6n. As a result, a number of studies of the various aspects of modern Korean society, particularly in its contacts with theW est, have been undertaken but little attention has been given to the evolution of that society. Yet it is only when this is studied for each period inK orean history that studies of contemporary Korean society can be approached in other than a limited sense. The Kory6 )period (918-1392) during which theM ongol invasions occurred was a great formative period in the history of the development of Korean society. The period encompassing theM ongol invasions of the thirteenth century and the subsequent establishment of Mongol military-administrative organs on the Korean peninsula was one of the important phases of transition inK orean history. The development of any society is, of course, continuous, but for the purposes of study I have found it convenient to treat the subject at hand in two natural divisions. The Mongol invasions of Korea in the thirteenth century as a development inK orean history form the subject of the present study. It is my intention to treat, in a separate work, the full extension of Mongol control inK orea which followed the period of conquest and with which I have dealt only summarily if at all in these pages. For the period covered I have, however, considered the question of the form and nature of Mongol demands upon Koryd as well as the implementation of these demands as (Typographical errors above are due to OCR software and don't occur in the book.)