This volume gives an account of the first of the Chinese united empires, known respectively as the Ch'in, Former Han, Hsin, and Later Han dynasties. (The terms Western and Eastern Han sometimes appear in place of Former and Later Han.) The obvious dates marking the beginning and the end of the period are those of two key events: the establishment of the Ch'in empire in 221 B.C. and the abdication of the last Han emperor in A.D. 220. However, these two specified years should not be taken as the rigid limits of the period that is covered by this volume. The events of 221 B.C. were the culmination of developments of the preceding centuries, and of necessity the first chapter of the book refers readers to the incidents, personalities, and developments of the Warring States period. Similarly, although the abdication of Hsien-ti may be regarded as the formal end of the Han dynasty, the process of imperial disruption was already far advanced long before that date; it may even be maintained that in real terms the outbreak of the revolt of the Yellow Turbans, in A.D. 184, marked the end of Han imperial authority. In considering the political developments of these last decades, when a powerless emperor still occupied the Han throne, it is essential to look forward to the succeeding period, when the disruption of the Han empire had finally taken place and its territories split between the three coexistent kingdoms of Wei, Shu-Han, and Wu.