Mongol conquests

The Mongol conquests of the 13th and 14th centuries built the largest land empire ever seen, the Mongol Empire, which by 1260 covered a huge stretch of Eurasia. At its peak, this territory reached from the Pacific Ocean into Central Europe. After 1260, the empire began to break apart, but fighting between Mongols and Eastern European states went on for centuries. Mongol rule in China lasted into the 1300s under the Yuan dynasty, while Mongol control in Persia continued into the 1400s under the Timurid Empire. In India, the later Mughal Empire, which had Mongol roots, survived into the 1800s.

The people who became the Mongols first appear in records in the late 900s, moving from eastern Manchuria onto the Mongolian Plateau. They settled southeast of Lake Baikal, near the mountain Burkhan Khaldun. During the 1100s, the Mongols grew powerful as their khans formed alliances and raided the Chinese Jin dynasty. This first confederation ended in the 1160s when the khans Qutula and Ambaghai were killed. The Mongols fell into poverty; other tribes like the Naimans in the west and the Kerait in the center became stronger, while the Mongols competed with smaller groups such as the Merkit and the Tatars, who were Jin allies, in the east and north.

One nephew of Qutula Khan, Yesugei, fought the Tatars with some success and was a close friend of Toghrul, the khan of the Kerait. With his wife Hö'elün—whom he had taken from her previous Merkit husband—Yesugei had several children, including a son named Temüjin (later Genghis Khan), born around 1162.

When Temüjin was still young, Tatars poisoned Yesugei, and Hö'elün’s family was abandoned by their tribe on the steppe. They survived attacks from other tribes and the harsh environment, while Temüjin killed his older half-brother to secure his own position. As an adult, Temüjin allied with Toghrul of the Kerait and an old friend, Jamukha, who now led his own tribe. Together they rescued Temüjin’s new wife Börte, who had been kidnapped by Merkit raiders in revenge for Hö'elün’s abduction.

The victory over the Merkit gave Temüjin prestige and many followers. Though he and Jamukha stayed close at first, their ambitions soon clashed and turned hostile. In 1187, Jamukha decisively defeated Temüjin, who fled to China. Sponsored by the Jin, he returned to the steppe in 1196 and, with Toghrul, led a successful campaign against the Tatars that same year, restoring his reputation. Over the next five years, Temüjin and Toghrul steadily grew more powerful, culminating in a 1201 victory over a coalition led by Jamukha. In 1202, Temüjin wiped out the Tatars, making the Mongols the leading force in eastern Mongolia. His relationship with Toghrul broke down in 1203, but Temüjin avoided defeat and subdued the Kerait. The Naimans were conquered, and Jamukha was executed within the next two years. With these wins, Temüjin became the unchallenged ruler of a newly unified people—the Mongol Empire.

The Mongol military overcame the usual weaknesses of nomadic armies and built on their strengths to become one of history’s most fearsome fighting forces. Earlier nomadic armies relied on horse-archers—armored cavalry who shot quickly and accurately with composite bows—often overwhelming enemies with speed, ambushes, or feigned retreats. But they struggled with siege warfare, holding conquered territory, and especially lacked discipline, which often led to disunity or collapse after a defeat. The reforms started by Genghis Khan fixed these problems, and the army kept evolving to meet new threats or opportunities. According to historian Christopher Atwood, this created “a vision of comprehensive warfare unique in the Middle Ages.”

For Genghis Khan, Atwood argues, war was a personal revenge against rulers who had insulted him or the Mongols. The shift toward world conquest was gradual; David Morgan suggests the Mongols “came round to the idea when they found that they were, in fact, conquering the world.” The idea grew more appealing as the Mongol army kept winning. By the time of Güyük Khan (ruled 1246–1248), it had become official ideology, as he told the papal envoy Carpini: “From the rising of the sun to its setting, all the lands have been made subject to me. Who could do this contrary to the command of God?”

Every adult Mongol man was a soldier; when not called up, he returned to his traditional herding life. Soldiers got no pay except plunder, which was divided after battle based on each man’s contribution. Most were horse-archers, having learned to ride as children. The small Mongolian horse was strong, quiet, and very hardy—though usually unshod, one could travel 600 miles in nine days. A Mongol soldier typically brought five or six horses on campaign, riding them on alternate days. Mistreating horses, like eating before tending to them, could be punished by death.

The Mongol composite bow, made of wood and horn, had a normal range of about 325 meters, but in good conditions could reach 530 meters. Every soldier carried at least one bow, along with two or three quivers of arrows. Most arrowheads were ordinary, but the Mongols also used special arrows that whistled, stunned, or pierced armor.