In the pre-war system of Europe the question of the Hapsburg Empire was hardly less complicated or less pressing than the so-called Eastern Question, though somehow it never aroused the same general interest. As it affected the whole political organization of the Danubian Basin it bore directly upon the international alignment of the powers and constituted a great danger to peace so long as a settlement was not reached. During the last years a number of very good books have appeared which have described the effect of the war on the Dual Monarchy, the collapse of the Hapsburg Empire and the emergence of the new succession states. These books have done much to elucidate the problem, especially as it touched the general question of national self-determination. The present book, however, deals with the background rather than with post-war developments. It is a really excellent piece of work, which will open up many new aspects of the question for the English and American reader. Jászi had distinguished himself before the war by his penetrating and enlightened writings on the Hapsburg problem, and served as Minister of National Minorities in the ill-fated Karolyi cabinet of 1919. In this book he discusses the historical development of the question, laying stress not only upon the racial aspect, but upon the potent economic and psychological factors. No student of Central European affairs should fail to read the book, which shows unusual grasp and exceptional breadth of view. The extensive bibliography, too, should prove a valuable aid to further study.