Mongol conquest of the Jin dynasty

The Mongol conquest of the Jin was a war of more than two decades between the new Mongol Empire and the Jin dynasty, which ruled northern China. It began with Genghis Khan’s invasion in 1211 and ended in 1234, when the last Jin emperor died at Caizhou in modern Henan.

It was one of the first great campaigns of the Mongol Empire and the longest of Genghis Khan’s wars. Unlike quick raids, it gradually forced the Mongols to learn how to besiege walled cities and govern settled farming populations. It also opened the way for the Mongol conquest of the Southern Song and the founding of the Yuan dynasty.

The war was fought across the densely populated plains of northern China. Along with the battles, it brought widespread destruction, famine and disease, and it is remembered very differently in Mongolia, China and elsewhere.

The Jin dynasty was founded in 1115 by Wanyan Aguda, a leader of the Jurchen people of Manchuria, who rebelled against the Khitan Liao dynasty. The Jurchen destroyed the Liao by 1125 and then attacked Song China, capturing its capital Kaifeng and two Song emperors in 1127. The Song retreated south of the Huai River, and the Jin ruled northern China. The name Jin means “gold”.

The Jin was a multi-ethnic empire. The Jurchen were a small ruling minority, organised militarily in hereditary units; Khitan, Bohai and other peoples held important roles; and the great majority of the population were Han Chinese farmers and townspeople. The Jin adopted many Chinese institutions, including civil service examinations, and moved their main capital to Zhongdu (on the site of modern Beijing) in 1153.

By around 1200 the Jin was large and populous, but it faced serious problems: a disastrous change in the course of the Yellow River in 1194, financial troubles including inflation of paper money, tensions between Jurchen and non-Jurchen subjects, and a war with the Song in 1206–08.

The Jin had long tried to control the peoples of the Mongolian steppe by supporting some tribes against others and by occasional punitive campaigns. Mongol tradition, recorded in the Secret History of the Mongols, remembered that a Jin emperor had put to death the Mongol leader Ambaghai, a relative of Genghis Khan’s ancestors, and this grievance was invoked as a reason for revenge.

In 1206 Temüjin united the Mongol and Turkic tribes of the steppe and was proclaimed Genghis Khan. He then attacked the Tangut state of Western Xia, which submitted in 1209–10, breaking up the Jin’s western buffer. When a new Jin emperor, Wanyan Yongji, came to the throne and sent envoys demanding submission, Genghis is said to have refused scornfully.

Historians point to several motives beyond revenge: the wealth of northern China, which could reward the Mongol elite and followers; the need to keep a newly united confederation busy and loyal through successful campaigns; and a desire to end Jin interference on the steppe. Some environmental historians have also suggested that unusually favourable weather on the steppe in the early thirteenth century increased the grass and horses available to the Mongols, though this is still being investigated.

In 1211 Genghis Khan led his army across the Gobi. At the Yehuling (“Wild Fox Ridge”) campaign, north-west of Zhangjiakou in modern Hebei, the Mongols defeated much larger Jin forces. The Jin records and Mongol accounts contain very large and contradictory numbers for the armies, so the size of the forces is uncertain. The Mongols broke through towards the Juyong Pass, the gateway to Zhongdu.

Over the next two years Mongol columns raided far across Hebei, Shanxi and Shandong, taking many towns but often leaving them again. Some Jin officers and Khitan subjects went over to the Mongols; a Khitan named Yelü Liuge rebelled in Manchuria and allied with Genghis. In 1213 a Jin general, Hushahu, murdered the emperor Wanyan Yongji, and a new emperor, Xuanzong, was enthroned.

In 1214 Xuanzong made peace, sending a princess in marriage to Genghis along with large payments of gold, silk and horses. Then, fearing for his safety, he moved the court south to Kaifeng. Genghis treated this as a breach of the agreement and returned. After a long siege, marked by famine inside the city, Zhongdu surrendered in 1215. The city was plundered and much of it burned; accounts speak of heavy killing, though precise numbers are unknown.

In 1217 Genghis Khan turned west against the Khwarazmian Empire and left the war in China to his trusted general Muqali, with the title guowang (“prince of the state”) and a modest army of Mongols supplemented by Khitan, Jurchen and Han Chinese troops. Muqali fought methodically, taking towns in Hebei, Shanxi and Shandong one by one.

A crucial feature of this phase was the role of local strongmen. As Jin authority collapsed, powerful families in northern China raised militias to defend their districts. Many of them, such as Shi Tianze, Zhang Rou and Yan Shi, went over to the Mongols and were confirmed as hereditary local lords. Others, such as the “Red Coat” rebels in Shandong, shifted between Jin, Song and Mongol allegiance. The war thus became a many-sided struggle for survival in the north.

The Jin made matters worse by fighting new wars against the Song (1217–1224) and Western Xia, hoping to gain resources in the south to compensate for losses in the north. Muqali died in 1223, and the Mongol advance slowed. Genghis Khan himself died in 1227 during a final campaign against Western Xia, which was destroyed that year.

Ögedei was chosen as Great Khan in 1229 and resolved to finish the Jin. The Jin had rebuilt their defence along the Yellow River and the passes to the west and won several victories, including at Daohuigu in 1231. The Mongols then devised a three-pronged attack. Ögedei advanced from the north, while his brother Tolui led an army in a great flanking march through Song territory in the Hanzhong region to enter Henan from the south-west.

Early in 1232 Tolui’s smaller force, shadowed by the main Jin field army under Wanyan Heda, avoided battle until the Jin troops were exhausted and short of food. At Sanfengshan, during a snowstorm, the Mongols attacked and destroyed the Jin army. This battle effectively ended the Jin’s ability to fight in the open field.

The Mongols, now commanded by Subutai, besieged Kaifeng from spring 1232. The defenders used gunpowder weapons such as “thunder crash bombs” thrown by catapults and “flying fire lances”, among the earliest recorded uses of such weapons in war. An epidemic broke out in the crowded city; the Jin official history claims that in about fifty days more than 900,000 bodies were carried out of the gates, a figure historians treat with caution but which shows the scale of the catastrophe.

Emperor Aizong fled Kaifeng at the end of 1232, and in 1233 the commander left behind, Cui Li, surrendered the city. According to later accounts, Yelü Chucai persuaded Ögedei not to massacre its population. The Southern Song, seeing a chance for revenge after the loss of the north a century earlier, allied with the Mongols; a Song army under Meng Gong joined the siege of Caizhou, where Aizong had taken refuge. In early 1234, as the city fell, Aizong handed the throne to a relative and killed himself; his successor died in the fighting the same day, and the Jin dynasty ended.

The war was devastating for the people of northern China. Cities that resisted were sometimes massacred as a warning to others; prisoners were driven ahead of armies to fill moats or man siege engines; and fields were abandoned as farmers fled or were conscripted. Siege and flight brought famine and epidemic disease, which probably killed more people than battles did.

The scale of population loss is one of the most debated questions. Jin registers of the early thirteenth century recorded several million households, and scholars estimate a population of perhaps forty to fifty million. The first Mongol census of northern China in the 1230s recorded only around one million households. This dramatic gap does not simply measure deaths: many people fled to the Song south, others became dependants of Mongol nobles or local lords and disappeared from state registers, and administrative chaos meant many were never counted. Historians such as James Waterson have warned against treating the difference as a death toll, while agreeing that mortality was enormous.

A famous story, told in the funerary inscription of Yelü Chucai, says that some Mongol officials proposed to empty northern China of its inhabitants and turn it into pasture, and that Chucai persuaded Ögedei that taxing the farmers would be more profitable. Whether or not the story is exact, it reflects a real shift from plunder towards taxation and administration.

The fall of the Jin gave the Mongols control of northern China, with its people, grain, craftsmen and engineers. Chinese and Khitan siege specialists and administrators became essential to later Mongol campaigns. Almost immediately, in 1234, a Song attempt to seize the old capitals Kaifeng and Luoyang provoked war between the Mongols and the Song, a conflict that ended only with the Mongol conquest of all of China in 1279.

The conquest also shaped the administration of Mongol China. Under Ögedei, Yelü Chucai organised tax offices and a census; lands and households were divided among Mongol princes as appanages; and the families of local strongmen who had joined the Mongols remained powerful for generations. When Kublai Khan founded the Yuan dynasty in 1271, he built his capital, Dadu, next to the ruins of Zhongdu, the origin of Beijing as a national capital.

For the Jurchen people, the fall of the Jin was the end of their first empire, but not of their history. Nearly four centuries later, the Jurchen leader Nurhaci named his new state the Later Jin (1616) in conscious memory of the earlier dynasty; his successors renamed their people Manchu and their state Qing, and went on to conquer China.

In Mongolia, the war belongs to the story of Genghis Khan’s creation of the Mongol state, and Genghis is honoured as the nation’s founder, especially since the end of socialist rule in 1990. The Secret History presents the campaigns partly as vengeance for past wrongs by the Jin, emphasising Mongol unity and loyalty.

In Chinese historical tradition, the picture is more complex. The Yuan dynasty itself sponsored official histories of the Liao, Jin and Song in the 1340s, treating all three as legitimate dynasties, and Genghis Khan received the temple name Taizu as the founder of the Yuan line. Later Chinese writers often lamented the destruction of the north, and the poet Yuan Haowen, who survived the fall of Kaifeng, wrote moving poems about the ruin of the Jin and worked to preserve its history. In the People’s Republic of China today, both Jurchen and Mongols are treated as part of China’s multi-ethnic past, and Genghis Khan is sometimes presented as a Chinese historical figure, a framing that is contested in Mongolia.

For the Southern Song, the fall of the Jin was first felt as revenge for the humiliation of 1127; the remains of Aizong were reportedly brought back and presented at the Song imperial ancestral temple. But the Song soon found themselves facing a far more dangerous neighbour. In Korea, the collapse of Jin power sent Khitan refugees and the short-lived Eastern Xia regime into the peninsula, leading to Goryeo’s first contact and joint action with Mongol troops in 1218–19, followed by the Mongol invasions of Goryeo from 1231.

The Secret History of the Mongols, the only major narrative written by Mongols in the thirteenth century, gives the Mongol perspective but is brief and sometimes vague about the Jin campaigns; its date of composition is itself debated. The Chinese Shengwu qinzheng lu (“Record of the Personal Campaigns of the Holy-Martial Emperor”) and the Persian history of Rashid al-Din (early fourteenth century) preserve related Mongol traditions.

The Jin shi (History of Jin) and the Yuan shi (History of Yuan) are the official dynastic histories. The Jin shi was compiled in 1343–44 under the Yuan chief minister Toqto’a, using Jin records and materials collected by Jin survivors such as Yuan Haowen. The Yuan shi was compiled hastily in about a year by the early Ming court (1369–70) and contains inconsistencies. Both use conventional numbers and formulae that must be read critically.

Contemporary observers add valuable detail. Song envoys wrote reports on the Mongols, such as Zhao Hong’s Mengda beilu (1221) and the Heida shilüe by Peng Daya and Xu Ting (1230s). Jin eyewitnesses such as Liu Qi, in his memoir Guiqian zhi, described the siege and fall of Kaifeng. Inscriptions, such as the funerary text for Yelü Chucai, preserve biographies of officials, though they tend to praise their subjects.

Why did the Jin fall? Traditional explanations stressed Mongol military superiority: mobile cavalry, discipline and ruthless strategy. Modern historians add the Jin’s internal weaknesses (court coups, fiscal crisis and paper-money inflation, the burden of wars on several fronts) and, above all, the defection of Khitan, Han Chinese and even Jurchen commanders, which gave the Mongols infantry, engineers and local knowledge. The Mongols’ adaptation to siege warfare, using Chinese and Central Asian techniques, is seen as a turning point in the history of their empire.

Did Genghis intend conquest from the start? Early Mongol campaigns in China often looked like large raids: the Mongols took cities and withdrew with plunder and captives. Some historians, following H. Desmond Martin’s classic study (1950), traced a gradual evolution from raiding to systematic conquest under Muqali and Ögedei. Others emphasise that Genghis’s aims in the east were always large, but that the Mongols lacked the means to occupy territory until they had recruited local allies.

The scale of destruction remains contested, as the population figures show. Older narratives presented the Mongols as uniquely destructive; newer work, while not minimising atrocities, examines migration, registration and the effect of epidemic disease, and compares Mongol practices with those of other armies of the time. The concept of “conquest dynasties”, introduced by Karl Wittfogel and Feng Jiasheng in their 1949 study of the Liao, has framed debates about the Liao, Jin, Yuan and Qing and the extent to which their rulers became “sinicised” or maintained distinct identities. The Jin, as both a conquering dynasty and a conquered one, stands at the centre of these discussions.