From their origins as just one of numerous tribes on the Central Asian steppes, the Mongols conquered an empire that extended from Poland in the west to Japan in the east. Their conquest of China was the longest campaign of all of their military actions, lasting 70 years from 1209 to 1279. In all of their campaigns, Mongol armies succeeded because of their military organization, adaptable tactics and divided enemies.
In the early 12th century, Mongol leader Kabul Khan led an alliance of Central Asian nomadic tribes to defeat an army from the Qin (also called Jin, Chi’in or Jurchen) kingdom in northern China. He died soon after and the alliance fell apart. In 1206, a “kuriltai,” a tribal leaders’ council, recognized Kabul Khan’s grandson, Temujin, as their Grand Khan, the supreme ruler. Temujin adopted the name Chinggis Khan -- also called Genghis Khan -- and prepared the Mongol confederation for their expansionary campaign.
China was split into two major power blocs during the early 13th century. The Qin Empire lay north of the Yangtze River with a capital at Yanjing, later to become Beijing. The Song Empire lay south of the Yangtze with a capital at Kaifeng. In 1126, the Qin captured Kaifeng, but the Song fought back from their new capital at Hangzhou. The state of Xi Xia, also called Western Xia, populated by Tangut people, lay in the northwest of China with a capital in Yinchuan.
Mongol soldiers were cavalrymen who trained in riding, hunting and fighting from earliest childhood. Military service was obligatory for all adult men. Each soldier brought several horses to any campaign for remounting, carrying supplies and as a food source. There was a separate messenger division for reconnaissance and intelligence gathering. Campaigns were planned and agreed in advance at a “kuriltai.” Mongols recruited Persian engineers to build catapults and rockets for use in siege warfare against the Chinese.
First China Campaign
Chinggis Khan’s Chinese campaign started in 1207 with the conquest of Xi Xia. In 1211, Mongols attacked the Qin Empire, recruiting Chinese engineers to destroy Qin city fortifications. They sacked Yanjing in1215 while the Qin retreated to the south. Mongol armies returned northwards to plan the 1218-21 westward campaign into Persia and the Caucasus. Chinggis Khan’s forces returned to China in 1224, defeating rebellions in Xi Xia and Qin over the next three years. Chinggis Khan died in 1227.
Second China Campaign
A 1227, Chinggis’ third son, Ogedai, also written Ogedei, became Grand Khan. In 1231 Ogedai allied with the Song to defeat the Qin Empire by 1234. That year, Song rulers attempted to capture some Qin territory. The result was a 45-year long war against the Mongols. Mongol armies invaded Central Europe at the same time, but this advance was halted by Ogedai’s death in 1241.
Third China Campaign
Ogedai’s son Mengke was appointed Grand Khan in 1251. Together with his younger brother Khublai, Mengke continued the war against China, conquering Nanchao -- today’s Yunnan -- and Tonkin -- northern Vietnam. Khublai became Grand Khan after Ogedai’s death in 1259. The war against China resumed in 1268, culminating in the capture of the Song capital Hangzhou in 1276. Land battles continued for the next three years until the last action in 1279 in Guangzhou Bay. A Mongol fleet consisting of Song defectors defeated the remnants of the Song navy. Khublai Khan became the first and last foreign ruler of China until his death in 1294.