Historians frequently change their minds, and long-term consensus on most important matters has been difficult to achieve. For example, until recently, pastoral nomads generally received bad press in history books. Normally they entered the story only when they were threatening or destroying established civilizations. In presenting a largely negative image of pastoral peoples, historians were reflecting the long-held attitudes of literate elites in the civilizations of Eurasia. Fearing and usually despising such peoples, educated observers in China, the Middle East, and Europe often described them as bloodthirsty savages or barbarians, bringing only chaos and destruction in their wake. Han Kuan, a Chinese scholar of the first century B.C.E., described the Xiongnu people as “abandoned by Heaven . . . in foodless desert wastes, without proper houses, clothed in animal hides, eating their meat uncooked and drinking blood.”38 To the Christian Saint Jerome (340–420 C.E.), the nomadic Huns “filled the whole earth with slaughter and panic alike as they flitted hither and thither on their swift horses.”39 Almost a thousand years later, the famous Arab historian Ibn Khaldun described nomads in a very similar fashion: “It is their nature to plunder whatever other people possess.”40

Because pastoral peoples generally did not have written languages, the sources available to historians came from less-than-unbiased observers in adjacent agricultural civilizations. Furthermore, in the long-running conflict across the farming/pastoral frontier, agricultural civilizations ultimately triumphed. Over the centuries, some nomadic or semi-agricultural peoples, such as the Germanic tribes of Europe and the Arabs, created new civilizations. Others, such as the Turkic and Mongol peoples, took over existing civilizations or were encompassed within established agrarian empires. By the early twentieth century, and in most places much earlier, pastoral peoples everywhere had lost their former independence and had often shed their nomadic life as well. Since “winners” usually write history, the negative views of pastoral nomads held by agrarian civilizations normally prevailed.

Reflecting more inclusive contemporary values, historians in recent decades have sought to present a more balanced picture of pastoralists’ role in world history, emphasizing what they created as well as what they destroyed. These historians have highlighted the achievements of herding peoples, such as their adaptation to inhospitable environments; their technological innovations; their development of horse-, camel-, or cattle-based cultures; their role in fostering cross-cultural exchange; and their state-building efforts.

A less critical or judgmental posture toward the Mongols may also owe something to the “total wars” and genocides of the twentieth century, in which the mass slaughter of civilians became a strategy to induce enemy surrender. During the cold war, the United States and the Soviet Union were prepared, apparently, to obliterate each other’s entire population with nuclear weapons in response to an attack. In light of this recent history, Mongol massacres may appear a little less unique. Historians living in the glass houses of contemporary societies are perhaps more reluctant to cast stones at the Mongols. In understanding the Mongols, as in so much else, historians are shaped by the times and circumstances of their own lives as much as by “what really happened” in the past.