The Inner Eurasian nomadic confederation known in ancient Chinese sources as the Yuezhi were probably descended from Indo-European-speaking pastoral nomads who migrated eastward away from the original homeland of all Indo-European-speakers sometime during the Bronze Ages. The ancestors of the Yuezhi may have been members of the Afanasevo culture who eventually settled in the modern Chinese provinces of Xinjiang and Gansu, and spoke the Indo-European language branch of Tocharian. The ruling dynasty (the core Yuezhi) established a wealthy semi-sedentary pastoralist confederation, based on the export of jade and horses to Zhou dynasty China, and became powerful enough to treat their militarized nomadic neighbors the Wusun and Xiongnu with “contempt.” This remained the situation until the 2nd century bce, when, according to Han dynasty annals, the resurgent Xiongnu were able to defeat the Yuezhi and force them to migrate away from their homeland. Following a thirty-year migration, the Yuezhi resettled in northern Bactria and by a century or so later they had reinvented themselves as the embryonic Kushan empire. These events were bound up with broader cultural and political developments in ancient Inner Eurasia that demonstrate the particular interconnectedness of historical processes in that region. The Yuezhi were well known to a range of contiguous peoples (generally by variants of the appellation “Tocharian”) and the events in which they found themselves involved, particularly during the 2nd century bce, were to have a profound effect on the subsequent political, military, and cultural development of much of Inner Eurasia. In particular, the “domino-effect” of their migration led to significant changes in the broader Eurasian polity, affecting the Han Chinese, Xiongnu, Wusun, Saka, Sogdians, and Bactrian Greeks. Because of these consequences, and their role in establishing the Kushan Empire, the great facilitators of Silk Roads trade and exchange, the Yuezhi must be regarded as one of the most significant of all Inner Eurasian pastoral nomadic confederations.