Genghis Khan attacked Xixia for two consecutive years in the second year after the founding of the People's Republic of China, forcing Xixia to surrender and pay tribute. After Genghis Khan lifted the flank threat, he began to wage war against the rulers. In the sixth year of Taizu (A.D. 12 1 1), Genghis Khan led General Muqali to attack gold. At that time, Jin concentrated his troops in Yehuling, with a population of 400,000. Muqali said that if you are outnumbered, you can't win unless you fight to the death, so he led the death squads to attack the enemy lines. Genghis Khan ordered the armies to storm, defeated 8 Jin Army and died in thyme. In the eighth year of Mao Zedong, the Mongols attacked Juyongguan, and Muqali sent the whole army around Zijingkou to defeat Gao Qi, a book tiger in Jinjiang. In the Battle of Uighur Fort, the nomads from the Jin Dynasty were defeated and advanced into Zhongdu (now Beijing). In the ninth year of Taizu, the ruler was forced to sacrifice his princess, gold and silk in exchange for peace and Mongolia's withdrawal. After Genghis Khan withdrew, Jin Xuanzong moved the capital to Bianjing (now Kaifeng). Genghis Khan attacked again and conquered Zhongdu the following year. He also sent Muqali to lead the troops to Liaodong and conquer Gaozhou. The following spring, Tokyo (now Liaoyang, Liaoning) was conquered, and Beijing (now Ningcheng West, Inner Mongolia) was besieged. Jin Jiangyin led 200,000 soldiers to refuse to fight, and Muqali defeated the nomads from the army, killing 80,000 enemies, and the defenders were forced to offer the city. Then, it captured a large area of land in Liaodong.
In the 14th year of Taizu (A.D. 12 19), Genghis Khan made a Western Expedition and ordered Muqali, a general, to continue fighting against Jin. Muqali changed the way that the Mongolian army used plunder and slaughter as the main means to obtain property, and established rule in the Central Plains. Shi Shi, the landlord of the Han nationality, stayed calm and stationed troops in the city. They have fifty-four counties and equal counties in the east. In the sixteenth year of Taizu, he joined forces with Xixia to attack Shaanxi. In the autumn of the following year, he went south to seize the state that Shanxi had not occupied before.
In the twentieth year of Taizu (AD 1225), Genghis Khan decided to destroy Xixia after returning to Li at the end of the Western Expedition. In the spring of the following year, Genghis Khan led more than 100,000 Mongolian armies from all walks of life to the south, crossed Helan Mountain, went east along Hexi Corridor, entered Lian Kai Shafu, Suzhou Prefecture, Gansu Prefecture and Xiliang, entered the Yellow River, and surrounded Zhongxing Prefecture (now Yinchuan, Ningxia). In the 22nd year of Taizu (A.D. 1227), Genghis Khan left some troops to besiege Zhongxing House, led other Mongolian troops to cross the Yellow River and capture the east of Xixia River. In the summer of the same year, Genghis Khan arrived in Liupanshan area and could not afford to get sick. Knowing that his time had come, he decided that his third son, Wokuotai, would inherit the throne. At this time, Xixia was brewing to surrender. In order to prevent accidents, he ordered himself not to send out mourning after his death, waiting for Xixia to surrender. Genghis Khan has been considering the strategy of eliminating the rulers for a long time. Before he died, he told his fourth son Tuo Lei the strategy of eliminating the rulers. Genghis Khan noticed that the main force of the rulers was concentrated in Tongguan, which was easy to defend but difficult to attack. He asked the Mongolian army to take advantage of the discord between Song and Jin, take advantage of the situation of Song, and detour to Kaifeng, Jindu, forcing the defenders of Jintongguan to come to the rescue thousands of miles away, and take advantage of their fatigue to break it in one fell swoop. After Yuan Taizong Wokuotai ascended the throne, he really defeated Jin Jun by using Genghis Khan's legacy. In the same year, Xixia kingdom died and Xixia died.
In the first year of Yuan Taizong (A.D. 1229), according to Genghis Khan's strategy of attacking gold, Yuan Taizong attacked gold in two ways, namely from Shandong and Shaanxi. At the same time, Tuo Lei was ordered to lead another army to the Hanzhong area in Song Dynasty, and Dengzhou invaded southern Jin. The main force of 8 Jin Army heard that the soldiers had arrived, and Li defended. The two armies fought bloody battles in the snow, and 8 Jin Army was defeated. Mongolian armies from all walks of life surrounded Bianjing and were under the unified command of Subutai. When Jin Aizong saw that Bianjing had run out of food, he set off for Germany and Cai Zhou. After the Mongols captured Bianjing, they joined forces with Song Jun to attack Cai Zhou. In the sixth year of Yuan Taizong (A.D. 1334), the city of Caizhou was broken and the state of Jin was destroyed. In the second year, Yuan Taizong ordered Prince Guo to attack the Jingxiang area in the Song Dynasty, and ordered Prince Kuo Duan to attack the Sichuan area from the north of Beijing. The Mongolian-Song War began.
Yuan Xianzong two years (AD 1252), Kublai Khan was ordered to go to dali. Dali is a political power established by the Bai people in Yunnan, and the national situation has declined at this time. Kublai Khan set out from Liupanshan in September of the same year, crossed the Yellow River in winter, went all the way south, passed Lintao and Teci (now Songpan, Sichuan), crossed Jinsha River and entered Yunnan. In the fourth year of Xianzong, Kublai Khan surrounded Dali City and soon broke the city. Duan Xingzhi, the Lord of Dali Kingdom, and Gao Taixiang, the powerful minister, broke through separately. Gao Taixiang was hunted down, Duan Xingzhi fled to be good at fighting (now Kunming), and Kublai Khan quickly issued a stop order after entering the city. The next year, he stayed in Uriyangqatai to guard Yunnan, and Kublai Khan returned to the north.
Uriyangqatai attacked the city in Yunnan, soon conquered the understanding, won Duan Xingzhi, and let him go if he didn't kill him. In the fifth year of Xianzong, Uriyangqatai was ordered to get through with the Mongolian army stationed in Sichuan. From Yunnan to the north, he captured Wumeng (now Zhaotong), entered Sichuan, and defeated the Song Shuijun in Xuzhou (now Yibin) until Chongqing. Soon, he attacked his toes south. After receiving the order, Xian Zongqin led an army to attack Shu and asked him to join forces in the north. Uriyangqatai passed through present-day Guixiang and attacked Ezhou (now Wuchang). After crossing the river, he joined Kublai Khan. Conquering the southwest made the Mongolian army form a strategic encirclement of the Southern Song Dynasty.
In the eighth year of Xianzong (AD 1258), Xianzong led an army into Sichuan and besieged Hezhou. Wang Jian, the general of Song Dynasty, led the army and civilians to defend Hezhou, which dealt a heavy blow to the invading Mongolian army and won a great victory in Fishing City. Xianzong died at the foot of the fishing city because he didn't adapt to the water and soil in the south, and the Mongolian army was forced to withdraw from the encirclement. Kublai Khan led the army to storm Ezhou, and the Song court sent Jia Sidao, a senior official, to supervise the rescue; Uriyangqatai attacked Tanzhou, and was also stubbornly resisted by Song generals to the scholar wall; The two sides launched a fierce offensive and defensive war in Jinghu area. Jia Sidao once sent people to pay tribute when Mongolia was unable to support it. The two sides made peace with Kublai Khan by rowing the Yangtze River. When Kublai Khan learned of the death of Xianzong, he was anxious to return to the north to compete for the throne, so he agreed to Jia Sidao's peace conditions and withdrew.
Kublai Khan acceded to the throne as Yuan Shizu and sent Hao Jing to the Song Dynasty, demanding the conclusion of a formal peace treaty. Jia Sidao detained Hao Jing, but Yuan Shizu sent a letter to Song Dynasty. In the second year of the unification of China (A.D. 126 1), Liu was demoted to Mongolia, so it was suggested to take Xiangyang first. From the 5th year of Zhiyuan (A.D. 1268), the Mongols began to besiege Xiangyang, cut off the connection between Xiangyang and the outside world, and repelled reinforcements from Song Jun many times. In the tenth year of the Yuan Dynasty, the Yuan army breached Fancheng, and the defenders of Xiangyang surrendered. In the same year, the Yuan Army launched a massive attack on the Song Dynasty. Under the leadership of Commander-in-Chief Bo Yan, the Yuan Army went down the Han River and entered the Yangtze River. After that, he settled in Mirror Lake in The Hague and Ali. Bo Yan led the main force down the river and fell along the Song Jun River. In the 12th year of Zhiyuan (AD 1275), Bo Yan and his Lu Yuanjun joined forces in Anqing, defeated the main force of Song Jun Navy in Dingjiazhou and swept the lower reaches of the Yangtze River. The following year, the Yuan army surrounded Lin 'an, and Song Gongdi started, and the Southern Song Dynasty perished. The resistance of the remnants of the Southern Song Dynasty in Sichuan and other southern regions was gradually put down. At this point, the Yuan Dynasty unified the whole country.