When
Ögedei Khan succeeded his father, he rebuffed Jin offers of peace talks but the Jin officers murdered Mongol envoys. Jin armies under Emperor Aizong successfully stopped several Mongol offensives, with major victories in the process, such as at the
Battle of Dachangyuan in 1229, Battle of Weizhou (1230),
Battle of Daohuigu (1231). The
Kheshig commander Doqolqu was dispatched to attempt a frontal attack on
Tong Pass, but
Wanyan Heda defeated him and forced
Subutai to withdraw in 1230. In 1231, the Mongols attacked again and finally took Fengxiang. The Jin garrison in
Chang'an panicked and abandoned the city, pulling back to
Henan Province with all the city's population. One month later, the Mongols decided to use a three-pronged attack to converge on
Kaifeng from north, east and west. The western force under
Tolui would start from Fengxiang, enter Tong Pass, and then pass through Song territory at the
Han River (near
Xiangyang) to reemerge south of Kaifeng to catch the Jurchens by surprise. Wanyan Heda learned of this plan and led 200,000 men to intercept Tolui. At Dengzhou, he set an ambush in a valley with several tens of thousands of cavalry hidden behind the crest of either mountain, but Tolui's spies alerted him and he kept his main force with the supply train, sending only a smaller force of light cavalry to skirt around the valley and attack the Jin troops from behind. Wanyan Heda saw that his plan had been foiled and prepared his troops for a Mongol assault. At Mount Yu, southwest of Dengzhou, the two armies met in a pitched battle. The Jin army had an advantage in numbers, and fought fiercely. The Mongols then withdrew from Mount Yu by about 30
li, and Tolui changed his strategy. Leaving a part of his force to keep Wanyan Heda occupied, he sent most of his men to strike northwards at Kaifeng in several dispersed contingents to avoid alerting Heda. On the way from Dengzhou to Kaifeng, the Mongols easily took county after county, and burnt all the supplies they captured so as to cut off Wanyan Heda's supply lines. Wanyan Heda was forced to withdraw, and ran into the Mongols at Three-peaked Hill in Junzhou. At this point, the Jin troops on the Yellow River were also diverted southwards to meet Tolui's attack, and the Mongol northern force under Ögedei Khan seized this opportunity to cross the frozen river and join up with Tolui – even at this point, their combined strength was only about 50,000. By 1232, the Jurchen ruler,
Emperor Aizong, was besieged in Kaifeng. They together smashed the Jin forces. Ögedei Khan soon departed, leaving the final conquest to his generals.
Mongol–Song alliance In 1233,
Emperor Aizong dispatched diplomats to implore the Song for supplies. Jin envoys reported to the Song that the Mongols would invade the Song after they were done with the Jina forecast that would later be proven truebut the Song ignored the warning and rebuffed the request. They instead formed an alliance with the Mongols against the Jin. The Song provided supplies to the Mongols in return for parts of Henan.
Fall of the Jin (1211–1215) Wanyan Heda's army still had more than 100,000 men after the battle at Mount Yu, and the Mongols adopted a strategy of exhausting the enemy. The Jin troops had little rest all the way from Dengzhou, and had not eaten for three days because of the severing of their supply lines. Their morale was plummeting and their commanders were losing confidence. When they reached Sanfengshan (Three-peaked Hill), a snowstorm suddenly broke out, and it was so cold that the faces of the Jin troops went as white as corpses, and they could hardly march. Rather than attack them when they were desperate with their backs to the wall, the Mongols left them an escape route and then ambushed them when they let down their guard during the retreat. The Jin army collapsed without a fight, and the Mongols pursued the fleeing Jin troops relentlessly. Wanyan Heda was killed, and most of his commanders also lost their lives. After the
Battle of Sanfengshan, Mongol troops took the city of Yuzhou. Kaifeng was doomed and Emperor Aizong soon abandoned the city and entered
Hebei Province in a vain attempt to reestablish himself there. Thousands of people offered a stubborn resistance to the Mongols, who entrusted the conduct of the attack to
Subutai, the most daring of all their commanders. Emperor Aizong was driven south again, and by this time Kaifeng had been taken by the Mongols so he established his new capital at Caizhou (present-day
Runan County,
Henan Province). Subutai wished to massacre the whole of the population. But
Yelü Chucai was more humane, and under his advice Ögedei Khan rejected the cruel proposal. The Jurchens used fire arrows against the Mongols during the defence of Kaifeng in 1232. The Mongols adopted this weapon in later conquests. In 1233, after Emperor Aizong had abandoned Kaifeng and failed to raise a new army for himself in Hebei, he returned to Henan and established his base in Guide (present-day
Anyang). Scattered Jin armies began to gather at Guide from the surrounding region and Hebei, and the supplies in the city could no longer feed all these soldiers. Thus Emperor Aizong was left with only 450 Han Chinese troops under the command of
Pucha Guannu and 280 men under
Ma Yong to guard the city, and dispersed the rest of the troops to forage in Su (in
Anhui Province), Xu (present-day
Xuzhou,
Jiangsu Province), and Chen (present-day
Huaiyang, Henan Province). Pucha Guannu then launched a coup with his troops, killing Ma Yong and more than 300 other courtiers, as well as about 3,000 officers, palace guards and civilians who refused to cooperate with him. He made Emperor Aizong a puppet ruler and became the real master of the Jin imperial court. At this point the Mongols had arrived outside Guide and were preparing to besiege the city. The Mongol general Sajisibuhua had set up camp north of the city, on the bank of a river. Guannu then led his 450 troops out on boats from the southern gate at night, armed with fire-lances. They rowed along the river by the eastern side of the city, reaching the Mongol camp early in the morning. Emperor Aizong watched the battle from the northern gate of the city, with his imperial boat prepared for him to flee to Xuzhou if the Jin troops were defeated. The Jin troops assaulted the Mongol camp from two directions, using their fire-lances to throw the Mongols into a panic. More than 3,500 Mongols drowned in the river while trying to flee, and the Mongol stockades were all burned to the ground. Sajisibuhua was also killed in the battle. Pucha Guannu had achieved a remarkable victory and was promoted by Emperor Aizong. But Guide was not defensible in the long term, and the other courtiers urged Emperor Aizong to move to Caizhou, which had stronger walls and more provisions and troops. Pucha Guannu opposed the move, afraid that his power base would be weakened and arguing that Caizhou's advantages had been overstated. The Han Chinese general
Shi Tianze led troops to pursue Emperor Aizong as he retreated, and destroyed an 80,000-strong Jin army led by Wanyan Chengyi (完顏承裔) at Pucheng (蒲城). Three months later, Emperor Aizong used a plot to assassinate Guannu, and then quickly began preparations to move to Caizhou. By the time new reports reached him that Caizhou was still too weak in defences, troops and supplies, he was already on the way there. The fate of the Jin dynasty was then sealed for good, despite the earlier victory against great odds at Guide. The
Southern Song dynasty, wishing to give the Jin dynasty the
coup de grâce, declared war upon the Jurchens, and placed a large army in the field. The remainder of the Jin army took shelter in Caizhou, where they were closely besieged by the Mongols on one side and the Song army on the other. Driven thus into a corner, the Jurchens fought with the courage of despair and long held out against the combined efforts of their enemies. At last, Emperor Aizong saw that the struggle could not be prolonged, and he prepared himself to end his life. When the enemy breached the city walls, Emperor Aizong committed suicide after passing the throne to his general
Wanyan Chenglin. Wanyan Chenglin, historically known as Emperor Mo, ruled for less than a day before he was finally killed in battle. Thus the Jin dynasty came to an end on February 9, 1234. == Mongol policies ==