When Liu Yu was on the northern expedition to Southern Yan, Murong Chao sent an envoy to the Later Qin Emperor Yao Xing for help because he had stayed in Later Qin in his early years, Yao Xing thought about it and sent a general to lead troops to help, and sent an envoy to Liu Yu's military camp, threatening Liu Yu and saying: "The Murong clan is friendly with neighbors, and it is urgent to attack the Jin Dynasty today, and Qin has sent 100,000 iron cavalry to Luoyang; If the Jin army does not return, it should be driven forward. (Zizhi Tongjian, Vol. 115). didn't think about it, but was slapped in the face by Liu Yu on the spot, and asked the messenger to go back and tell Yao Xing that after he destroyed Yan, he would take a truce for 3 years, and then he would go north to seize Luoyang and Guanzhong. If Yao Xing is willing to come to his death now, please come quickly!
Yao Xing. One. Of course, in the end, Yao Xing withdrew reinforcements to Nanyan because Helian Bobo was making trouble in the rear; And Liu Yu did not send troops to destroy Qin after 3 years as he said, and after the Northern Expedition really began, Qin was already six years after the destruction of Southern Yan. As for the purpose of Liu Yu's Northern Expedition to Qin, the historical circles are still debated, and most people, including Wang Fuzhi, believe that Liu Yu's Northern Expedition to Qin was to increase political bargaining chips for usurpation; A small number of people represented by Lu Simian believed that Liu Yu's Northern Expedition was still aimed at recovering his homeland, but the restrictions of later conditions did not succeed. Regardless of the purpose of Liu Yu's Northern Expedition, one thing is certain, that is, Hou Qin was not a small country like Southern Yan and Qian Shu, in fact, after the collapse of Hou Yan, Hou Qin was once the only big country in the north that could compete with Northern Wei. Later Qin Emperor Yao Xing was not a general person like Murong Chao and Chen Zong, he was friendly with the Buddhist giant Kumarosh, proficient in Buddhism, and the Later Qin was quite outstanding in his martial arts under his governance.
Kumarosh. The remnants of the former Qin Dynasty fought fiercely with Emperor Yao Chang of the Later Qin Wuzhao Emperor in Guanzhong for eight years, and there were mutual victories and defeats, and after Yao Chang's death, Yao Xing annihilated the Fu Deng in half a year; After ascending to the throne for the first time, various forces within the Qin regime were not convinced, Yao Xing did not mourn, and won over his uncle Yao Shuode, and settled the internal crisis in three or two; Sima Daozi's father and son rebelled, Yao Xing's troops went out of Tongguan and captured Luoyang, and the north of the Huai River and Hanshui were mostly attached to Hou Qin; The northwestern countries contended, Yao Xing destroyed the Western Qin, descended to the Liang, the Southern Liang, the Northern Liang, and the Western Liang successively called the ministers, Yao Xing and invited the Kumaro from Guzang to Chang'an to preach Buddhism, and for a time the Qin country was prosperous.
The previous Hou Qin's biggest enemy in the north, Hou Yan, has been greatly injured by the Northern Wei Dynasty, it can be said that at this time the Hou Qin is called the first power in the north, it is not too much, it seems that it can follow in the footsteps of the former Qin to unify the north. However, the battle of Chaibi shattered all this, in the fourth year of Hongshi (402), Yao Xing sent troops to compete with the Northern Wei Dynasty, and the two sides met in Chaibi (now Xiangfen South, Shanxi), and finally this became Yao Xing's "Shenhe Slope", after the Qin and Qiang soldiers were wiped out, and they were no longer able to march east to fight against the Northern Wei Dynasty, and actually lost the hope of seizing the Central Plains. The defeat in the war caused internal divisions within Later Qin, and in the ninth year of Hongshi (407), the Xiongnu Xia Kingdom, which Yao Xing had taken in, established by Helian Bobo in Shuofang, northern of Later Qin, continued to harass Later Qin; In the eleventh year of Hongshi (409), the beggar returned to the Western Qin, and the territory of Qin was greatly reduced for a while. At the same time, Southern Liang and Northern Liang also rebelled against Later Qin, Yao Xing was exhausted in many battles, but he still could not suppress the situation, in this case, the national strength of Later Qin was slowly losing, and Yao Xing also lost his early years of hard work in endless troubles, and paralyzed himself by preaching with Kumarosh.
It is impossible to expand the territory of the Later Qin Dynasty in this way, but because of the political means of Yao Xing, who is old and spicy, he can still protect himself. After Liu Yu's Northern Expedition, Qin must have the certainty of victory, and wait for a suitable time, Yao Xing finally died in the spring of the eighteenth year of Hongshi (416), and Liu Yu stepped on Yao Xing's corpse in the court to announce that the war against Hou Qin was about to begin.
Two. Before Yao Xing's death, the internal contradictions of Later Qin had broken out, Yao Bi, the younger brother of the crown prince Yao Hong, took advantage of the old emperor's serious illness and wanted to lead troops to break into the palace to seize power, Yao Xing took the illness to quell the rebellion, exhausted his last breath, and Yao Xing died of illness the next day. After Yao Xing's death, Nanyang Gong Yao Su and others plotted to cause chaos, and Yao Hong killed them all, winning another victory of cannibalism. The temporary calm inside was exchanged for the arrival of an external storm, and in May, Liu Yu held a military parade in Jiankang and swore to the Northern Expedition.
Yao Hong. On December 20 of the first year of Yonghe (416), the vanguard of the Eastern Jin Dynasty Northern Expedition led by Tan Daoji, Wang Zhenwei and Shen Linzi arrived in Luoyang, and the water of Luoyang was blocked. It is also time to count the Hou Qin gas, the winter of the Yellow River in the north is not suitable for the southern army to march, and the land of the Kwantung is lost, and the Hou Qin is still in the middle, if you want to enter the pass, you have to face the two major barriers of Tongguan and Hangu Pass, and the current strength of the Northern Expedition vanguard is not enough, and according to Liu Yu's plan, the Northern Expedition vanguard should be stationed in Luoyang at this time to wait for the spring of next year, and the Taiwei Liu Yu personally led the army to reinforce. However, the plan could not catch up with the changes, Yao Hong had two younger brothers, Yao Yi who guarded Hangu Pass and Yao Hui who guarded the northern frontier of Later Qin, the domestic situation is now unstable, and both younger brothers have a heart of disobedience, in the winter of the first year of Yonghe (416), Yao Yi launched a rebellion in Hangu Pass, trying to kill back Chang'an and replace Yao Hong; In the spring of the second year of Yonghe (417), Yao Hui raised troops in the north again, and because there were no soldiers available in Guanzhong, Yao Hong, who was helpless, had to urgently recruit the defenders of Hangu Pass and Tongguan to return to Guanzhong to quell the chaos.
Faced with such a favorable situation, several bold young men decided to take a risk, not waiting for the arrival of the army, and entered the pass ahead of schedule. Originally, they planned to lead the troops all the way west by Wang Zhenwei and pounce on Tongguan; Tan Daoji and Shen Linzi led the rest of the troops to cross the river to the north and attack Puban (Yongji, Shanxi), intending to cross the Yellow River from Puban to the west, bypass Tongguan, and jump directly into the hinterland of Guanzhong. However, as soon as Tan Daoji and Shen Linzi crossed the Yellow River, they were met with stubborn resistance from the Pusaka defenders. Seeing that there was no hope of attacking Pusaka, they had no choice but to return the same way, and once again join Wang Zhen's evil division and march towards Tongguan together. Originally, such a reckless advance should have been very beneficial to Hou Qin, and even Liu Yu was very dissatisfied with the actions of Tan Daoji and others after knowing it, because Hou Qin was very likely to take advantage of the time when the army did not arrive, and eliminate the Eastern Jin Dynasty forward.
However, just as a dynasty is invincible when it rises, it will be invincible in its final years. The Qin army tried every means to destroy this army, attacking their food routes, cutting off their water sources, and cutting them off from the main force, but all their strategies failed. When Liu Yu was on the north bank of the Yellow River and later broke the Northern Wei Dynasty with the famous "Moon Array" in the world, Wang Zhenwei and others had already broken through the Tong Pass, waiting for Liu Yu to arrive, Hou Qin's qi was really exhausted, in July Shen Tianzi led a group of thousands of people in Lantian Pass and Yao Hong of the imperial expedition to meet, Yao Hong brought tens of thousands of troops, vowing to hold this last line of defense, so what, Shen Tianzi conquered Lantian Pass in one fell swoop, Yao Hong fled back to Chang'an in a hurry.
In August, when Liu Yu led the main force to Tongguan, Yao Hong was already trapped in the lonely city, Liu Yu adopted the advice of Wang Meng's grandson Wang Zhenwei and sent him to lead the lead to attack Chang'an, in fact, what other backup troops are needed? Liu Yu's army had not yet reached Chang'an, and Wang Zhenxi, who had only more than 10,000 people, had already annihilated the last main force of Hou Qin who wanted to destroy him, and successfully entered Chang'an City. Now it's up to Yao Hong's choice.
Yao Hong had nothing to do and wanted to surrender to Liu Yu. His son Yao Fo Nian was only 11 years old, since he was a child, he followed his grandfather Yao Xing to learn Buddhism, and was deeply favored by his grandfather. (Jin Shu Yao Hong Records).
Yao Hong was dazed and did not answer, so Yao Fonian climbed the palace wall and threw himself to the ground. Yao Hong did not have the courage to commit suicide, he rode in a sheep cart, covered the wall, and carried the coffin, just like when Sima Ye, the emperor of the Jin Dynasty, surrendered to Liu Cong a hundred years ago, but the last victory was Hu Ren, and this time it was Liu Yu.
Yao Hong was sent to Jiankang's downtown to be beheaded like Murong Chao, but it is understandable that Murong Chao would rather die than surrender and be killed, but Yao Hong, who voluntarily surrendered, did not survive, of course, Liu Yu also did not let go of Hou Qin's clan.
Three. Recovering Chang'an is the pinnacle of Liu Yu's life, in the past hundred years since the Eastern Jin Dynasty moved to the left, how many heroes and heroes want to achieve this glorious goal, but after all, it has become a lifelong regret, 63 years ago, the world-famous big man can only sigh in Ba, Liu Yu did it. Its rise is also vigorous, and its death is also sudden, who would have thought that this is the biggest setback in Liu Yu's life. The so-called frustration does not lie in the gains and losses of the land in Guanzhong, but in the abandonment of Guanzhong and the loss of the last bit of the people's support in Guanzhong that "the remnants of the people do not touch the king".
More importantly, people, whether it is Wang Zhenwei and Shen Tianzi who died of cannibalism, or Zhu Lingshi, Zhu Chaoshi, Fu Hongzhi, Kuai En who died at the hands of Helian Bobo, and the legendary Mao Xiuzhi. In short, Liu Yu got the Southern Song Empire he wanted, but in a sense, it can also be said that Liu Song lost all the commanders of the Northern Expedition. Liu Yilong, the third emperor of the Liu Song Dynasty, the first person he wanted to kill every time he was seriously ill was Tan Daoji, and the root was also planted at this time.
References: "Zizhi Tongjian", "Book of Jin", "Book of Song", "On Liu Yu" (Zhu Shaohou), "History of the Northern and Southern Dynasties of the Wei and Jin Dynasties" (Wang Zhongju), "History of the Northern and Southern Dynasties of the Two Jin Dynasties" (Lü Simian), "History of the Later Qin" (Oqiong Zhuoma), "Wolf Palace" (Lü Qinghou).