The Origins of the Mongol People

In the early 13th century, a dramatic shift was unfolding across Eurasia. While the Southern Song Dynasty in China’s south prepared defenses against the Jurchen-ruled Jin Dynasty, the Jin themselves braced for attacks from an even greater northern threat—the Mongols, who would soon dominate the continent.

The Mongols traced their roots to the Shiwei tribes, particularly the “Mengwu Shiwei,” who inhabited the grasslands near Lake Hulun and the lower reaches of the Argun River during the Tang Dynasty (618–907 CE). Originally, these tribes relied on hunting, fishing, and pig farming, with little use for horses—a far cry from the mounted warriors they would later become. However, between the 8th and 9th centuries, as the Turkic, Uyghur, and Kyrgyz empires collapsed, the Shiwei migrated westward into the Mongolian Plateau, blending with remnants of Turkic peoples and adopting a nomadic pastoral lifestyle.

The Transformation of Mongol Society

Over time, interactions with Chinese, Turkic, and Uighur civilizations reshaped Mongol society. The traditional clan-based structure disintegrated, giving way to a new aristocracy—the noyan (nobility)—who commanded vast followings of warriors, slaves, and free subjects. The steppes became a battleground of rival factions, described vividly in The Secret History of the Mongols:

“The starry heavens turned, the people rebelled, plundering each other’s possessions. The grassy earth churned, the people fought, no longer sleeping peacefully in their tents.”

Amid this chaos, a leader emerged who would unite the warring tribes under a single banner: Temüjin, later known as Genghis Khan.

The Rise of Genghis Khan and the Mongol Empire

By the early 1200s, Genghis Khan had consolidated control over the eastern steppes, from the Hulun Buir grasslands to the Altai Mountains. His new state, Yeke Mongγol Ulus (Great Mongol Nation), was unprecedented in its unity and military discipline. After subduing the Western Xia Dynasty to eliminate a potential threat, he turned his attention to the Jin Dynasty—the dominant power in northern China.

Two foreign chroniclers recorded the Mongol preparations for war. Juzjani, a historian of the Delhi Sultanate, described a solemn ritual before the invasion:

“Genghis Khan ordered all Mongol families to gather at a mountain. For three days and nights, men and women were separated, children from mothers, with no adornments worn. No food was consumed, and livestock were denied milk. Genghis Khan himself remained in a tent, a rope around his neck, while the people cried out to Tengri (the sky god). On the fourth day, he emerged, declaring victory granted by heaven.”

Rashid al-Din, a Persian vizier under the Ilkhanate, added that Genghis Khan framed the war as divine retribution:

“Tengri, you see that the Altan Khan (Jin emperor) has wronged us. He executed my ancestors unjustly. If my cause is just, grant me victory!”

The Mongol Invasion of the Jin Dynasty

Historical grievances played a role in Mongol aggression. The Jin Dynasty had long conducted brutal “population reduction” campaigns (mie ding) in the steppes and executed key Mongol leaders, including Genghis Khan’s ancestors. Yet, like later conquerors such as Nurhaci of the Manchus, Genghis Khan also used these grievances strategically to rally his forces.

In 1211, the Mongols crossed the crumbling Jin fortifications—abandoned remnants of the northern frontier—and launched their assault. Though their army lacked uniform equipment (fewer than one in ten soldiers wore armor), their mobility and ferocity were unmatched. Key commanders like Muqali, Bo’orchu, and the legendary “Four Dogs” (Jebe, Kublai, Jelme, and Subutai) led devastating campaigns that would soon extend from the Pacific to Europe.

Cultural and Military Legacy

The Mongol conquests reshaped Eurasia. Their tactics—speed, psychological warfare, and integration of conquered peoples—became a blueprint for future empires. The Pax Mongolica facilitated unprecedented trade and cultural exchange along the Silk Road.

Yet, Genghis Khan’s motivations remain debated. While he invoked ancestral vengeance, his own words in informal settings suggest a more primal drive:

“The greatest joy for a man is to defeat his enemies, seize their wealth, hear the lamentations of their women, and ride their finest horses.”

Conclusion: The Mongol Impact on World History

The Mongol Empire’s rise marked a turning point in global history. From fragmented tribes to a world-conquering force, their legacy endures in military strategy, trade networks, and the cultural exchanges that defined the medieval world. The ruins of the Jin frontier walls, as later travelers noted, stood as silent witnesses to the unstoppable tide that reshaped Eurasia.