The Spring and Autumn Warring States period was a period of great division in Chinese history, from 770 BC to 221 BC, up to 550 years, this period is actually divided into the Spring and Autumn Period and the Warring States Period, the watershed was in 453 BC, Han, Zhao, Wei three families destroyed the Zhi clan, divided the Jin state as a symbol. The original Spring and Autumn Five Hegemons gradually developed into the Seven Heroes of the Warring States, the Spring and Autumn Five Hegemons Qi Huan Gong, Song Xiang Gong, Jin Wen Gong, Qin Mu Gong and Chu Zhuang Wang, and in the Warring States period, the Qi State, the Chu State, the Qin State, the Yan State, the Korean State, the Zhao State, the Wei State, the new and old forces are constantly changing, and only those who can survive can continue to fight.
Since the Spring and Autumn Period, the State of Qin has become a Western power, although it has not become the head of the Spring and Autumn Five Hegemons, but during the period of hegemony of several other major princely states, the State of Qin has been accumulating strength and developing power. In the Warring States period, since the Shang martingale changed the law, the backward old system was completely abolished, the economy developed, the national strength was strengthened, and the Qin state became the strongest country among the seven kingdoms, and began to expand its power to the east, first defeating the Three Jins, and then continuing to expand its territory to the west, south and north, and by the end of the fourth century BC, its territory was close to that of the Chu state.
Speaking of the State of Chu, the State of Chu is also a veteran aristocratic princely state, during the Spring and Autumn Period, the State of Chu expanded its power and developed hegemony, and there were many allies, and it already had the strength to dominate the Central Plains, but when it encountered the developed State of Jin, it formed a situation of "Jin-Chu Contending for Hegemony", and later it was jointly attacked by several countries, and the national strength of the State of Chu was greatly weakened. In the Warring States period, although the vast and populous Chu state did not have the strength to compete for hegemony, among the seven kingdoms, the key point of the qin and Qi countries' hegemony was the chu state, and if anyone could develop the chu state into an ally, then hegemony was just around the corner. The Chu state chose to unite against Qin, which greatly affected the subsequent development of the Qin state.
At that time, in order to balance the development of the Qin state, the other six kingdoms, in order to balance the development of the Qin state, through Su Qin's lobbying of the Six Kingdoms, as well as the promotion of Gongsun Yan and others, the six kingdoms implemented a policy of vertical alliance to oppose the powerful Qin state, that is, "unity and vertical", and Zhang Yi's Lian Heng plan was aimed at this strategy, because the purpose of Lian Heng was to serve a strong country as a backer and attack other weak countries, in order to achieve the purpose of annexing and expanding land. Therefore, some countries seek development, and they choose to cooperate with the Qin state, so that the "unity" of the six countries is destroyed. Among these combined countries, the State of Chu really made people hate iron not steel, and the princes of Shandong resisted Qin five times, and the State of Chu took the initiative to escape three times.
In 318 BC, under the conspiracy of Gongsun Yan, led by the State of Chu as the longitudinal commander, The State of Korea, the State of Zhao, the State of Wei, the State of Yan, and the State of Qi led the Xiongnu to attack the State of Qin together, and the State of Qin produced many famous generals, naturally there was no shortage of generals who could win the battle, And Li Li analyzed the weaknesses of the coalition forces, and planned to break through each of them, the first thing to deal with was the State of Chu, which was about to be longitudinal, once the leaders were all beaten, then the coalition army would be scattered, the Qin army took the initiative to attack the State of Chu, and the timid and cowardly King Huai of Chu fled with the Chu army, so The joint operation was also shattered.
In 298 BC, Meng Yijun united with the State of Qi, Korea, and the State of Wei to attack the State of Qin, at this time the State of Qin had just ended its civil unrest, soon after King Zhaoxiang of Qin ascended the throne, Empress Xuan purged the opposition forces of the court, and it took three years, in this battle, the State of Qin did not win, and the General Kuang Zhang of The Central Qi Led the Coalition Army to attack the Hangu Pass of the State of Qin, forcing the State of Qin to make peace, and the coalition army won a great victory, but they did not take advantage of the victory to attack, otherwise they would definitely seriously damage the State of Qin. In this way, it seems that the combination of the two is indeed an effective policy to balance the Qin state, as long as they work together, the worst is to lose both sides.
In 287 BC, Su Qin lobbied Qi, Zhao, Wei, Han, and Yan to join forces to resist Qin, but this great war did not really happen, because Su Qin's real purpose was the State of Qi, and the State of Qin faced the attack of the Five Kingdoms, naturally did not go hard, but symbolically cut several cities, canceled the imperial title, and then the coalition army went to deal with the State of Qi, this battle really hit the State of Qi, the State of Qi completely lost its status as a strong country, the real threat of the State of Qin was eliminated, and the development of the State of Qin was more smooth in the future.
In 247 BC, the State of Qin attacked the State of Wei, Xin Lingjun united with Zhao, Chu, Yan, and Han, and the five-nation alliance army once again targeted the Qin State, under the leadership of Xin Lingjun, it fought all the way to the west of Hangu Pass, but it could only be fought here, because the coalition army was far away, grain and grass must be a big problem, their grain and grass could not be received, and the contradictions between the five kingdoms also began to appear, so this time the alliance was not happy and dispersed, and they missed the opportunity to destroy Qin again. The rulers of the Qin state also realized that Xin Lingjun was a character, so they alienated the King of Wei, and Xin Lingjun was stripped of his military power, and after his death, several countries could not reach a consensus under the attack of the Qin state, and the pace of the Qin state's occupation of the six kingdoms began to accelerate.
In 241 BC, under the organization and planning of Pang Yan, han, Zhao, Wei, Chu, and Yan once again joined forces against Qin, and this time the leader was still the State of Chu, the Chunshen Jun of the Chu State was famous enough, but once again let the Qin State find the entry point, Lü Buwei revealed the news of the attack on the Chu State to Chun Shen Jun, Chun Shen Jun was afraid that the Chu King would be attacked, so he persuaded the Chu King to retreat, and by the time the Qin State went to attack the Chu State, the Chu State had already fled, and the Qin army could only attack the Zhao State, although it had one less ally, but under the command of Pang Yan, Fortunately, there was no collapse, and both sides were defeated, and this time the alliance was once again abandoned.
The strength of the Chu state is not bad, but unfortunately it has always been afraid of the tough Qin state, in the last joint strategy, in fact, there is no need to escape, it is completely possible to communicate with Pang Yan, surround the Qin state, and then there is a coalition army behind them, how can they not deal with a Qin state? It's just a pity that the princely states really can't work together to complete a successful conspiracy and eliminate the biggest threat, the Qin state, so that they will not be destroyed one by one by the Qin king Yingzheng in the future.