The battle of Changping was not a war during the reign of Ying Zheng, but it was a far-reaching war. This war is the largest and longest-lasting war in the Warring States period, and it is also the most difficult war encountered in the process of Qin's unification of the six countries, and it is also a war in which Qin and Zhao compete for the right to reunification. Whoever wins is more likely to unify the world. Therefore, the preparation, investment and attention of the two countries to this war are unprecedented. Before the war, let's take a look at the strength comparison between the two countries.

This is a war that lasted for three years and involved nearly one million troops. So it is not just a military confrontation, but a contest of comprehensive national strength.

First of all, let's compare the economic strength of both sides before the war.

Qin is located in Yongzhou, one of Kyushu. It used to be the capital of the Zhou Dynasty, with fertile land and rich products. After Shang Yang's political reform, Qin became rich and strong rapidly. In the battle of Changping, Qin had the land of Bashu in the south and the land of abundance. Under the policy of attaching importance to agriculture, Qin has abundant grain, solid economic foundation and abundant strategic materials. After the completion of Zheng Guoqu and Dujiangyan, Qin's water conservancy has been developed, which not only ensures agricultural production, but also facilitates the transportation of military supplies.

Zhao is located in Jizhou, one of Kyushu. The land is not as fertile as Guanzhong and Bashu of Qin State, and even worse than Qi State in the east and Wei State in the south. Moreover, the folk custom of Zhao is, "Anger makes Ren Xia a traitor, not a farmer." . Zhao is a country that pays equal attention to agriculture and commerce, and there is no policy similar to Qin. People have little enthusiasm for agriculture. Therefore, Zhao's agricultural economy is relatively backward among the six countries, and its combat readiness reserve is insufficient, which cannot support a long-term large-scale war.

Therefore, in the economic field, Zhao's strength is not as good as Qin's. However, in terms of logistics support in the war, Zhao is the defensive side, and the material consumption is much smaller than that of Qin. Considering this, it can be considered that the two sides are equally powerful in logistics support.

Secondly, let's compare the military strength of both sides.

Needless to say, Qin Jun's strength has historically included its "more than one million warriors, thousands of cars and 10,000 horses". Moreover, Qin people are close to the northwest, and the folk customs are tough. After Shang Yang's political reform, stimulated by the military knighthood system, Qin Jun became the invincible master of tigers and wolves, and was a super military power at that time.

After King Wuling of Zhao's political reform, Zhao's military power rose rapidly, with "hundreds of thousands of armor, thousands of cars and tens of thousands of horses". Zhao learned from Xiongnu and established cavalry units earlier. In addition, Zhao's cavalry are mostly bow-riding, flexible, well-trained and with high military literacy.

As far as the size of the army is concerned, Zhao is slightly inferior, but as far as generals are concerned, Zhao is not inferior. At that time, there were Bai Qi and Wang Bi in Qin, and Lian Po and Li Mu in Zhao. Judging from prestige alone, the quality of general Zhao seems to be higher than that of Qin.

In addition, it should be considered that Zhao is the defensive side, and the army can take advantage of the terrain when fighting in its own country (as Lian Po did).

Therefore, combined with geographical advantages, Zhao's military strength can also be said to be equal to Qin's.

Third, let's look at the comparison of political power between the two countries.

When the Changping War broke out, Qin was the king of Qin Zhao. Wang Zhao is wise, Qin is politically clear, the country is stable, and there are no traitors in North Korea. But Zhao's situation is different. At this time, the wiser King Huiwen had just passed away, and was succeeded by a dutiful son with mediocre intelligence. There were traitors in the DPRK. If Qin scored 90 points for his political ability, Zhao Xiaocheng may have just passed. It is the gap in political power that has laid a hidden danger for Zhao Jun's failure.

Qin has been nibbling away at the weak South Korea and the aging Wei State since it established the strategy of far-reaching and near-attacking. In 268 BC, Qin Jun captured Huai and Xing Qiu of Wei, and under the pressure, Wei attached to Qin for safety. He led his troops south and successively captured Hong, Gaoping, Shaoqu and other places.

In 26 1 year BC, Qin Jun conquered Yewang, a strategic place in South Korea, divided South Korea into two parts, and Shangdang area was completely separated from South Korea. The South Koreans were in a panic, and the King of Korea immediately sent an envoy to the State of Qin, hoping to achieve a truce between the two countries by giving Shangdang County, so as to continue to linger.

If South Korea really succeeded in handing over Shangdang to Qin, maybe everything would be easy. However, Feng Ting, the satrap stationed in Shangdang, South Korea, is not a simple figure. He didn't want to dedicate Shangdang to Qin, but made his own decision and dedicated Shangdang to Zhao, who could compete with Qin. His intention is very clear, that is, he hopes to attack Qin with the help of Zhao's strength.

Zhao's decision caused quite a controversy in the ruling and opposition circles. Zhao Bao believes that "China will never associate with the land occupied by the State of Qin, thinking that it will take the position of the Party", which will inevitably lead to the retaliation of the State of Qin, so it is better not to accept it. However, Ping Yuanjun, Zhao Sheng and others believe that Shangdang is a strategic place and there is no need to gain nothing. Finally, the Prince of Zhao accepted Ping Yuanjun's suggestion and sent Zhao Sheng to take Shangdang County into his own territory. The prince of Zhao named Feng Ting as Hua Yangjun, who ate 30,000 households, and the officials and people named him third class.

Zhao's move is tantamount to grabbing food from the tiger's mouth. In order to seize Shangdang area, Qin divided South Korea into two parts. Now Shangdang belongs to Zhao, and cooked ducks fly like this. Of course, the king of Qin was angry. At the suggestion of Fan Sui, the king of Qin ordered the army to attack Zhao.

In 262 BC, the Qin army attacked South Korea in two ways, all the way to Xingyang, and another route leader, Wang Bi, jumped on the party. Shangdang Zhao could not resist the attack and had to retreat to Changping. In this way, the fuse of the largest and most tragic war in the Warring States period was ignited.

When the prince of Zhao learned of the attack on Shangdang, he sent Lian Po to lead Zhao's main force to Changping, hoping to recapture Shangdang.

In the spring of 260 BC, Lian Po began to deploy troops at the front line of Kongcangling. Wang Bi led an army to attack Kongcangling, and the defenders of Zhao were overwhelmed and retreated step by step. In July, dozens of miles of Kongcangling were breached, and Zhao retreated to the Danhe River to save his troops. Qin Jun attacked the fortress one after another, with heavy casualties. We need to have a rest. As a result, the two armies began a confrontation across the river. Zhao under the command of Lian Po, relying on the Danhe River, built fortifications and fully defended. No matter how provocative Zhao is, he just doesn't take the initiative to fight.

Faced with this situation, Wang Bi was at a loss. At this point, the war entered a stalemate. This confrontation lasted for three years, and both countries began to worry about logistics supply. Qin's economy has been overwhelmed. According to historical records: "Although the Qin Dynasty broke the Changping Army, the Qin people were half dead and the country was empty." "Lu's Spring and Autumn Annals" also wrote: "Although Qin wins Changping, it will be decided after three years, and scholars are tired of food." Zhao's economic strength is not as good as Qin's, and it has reached the point of "no food, please don't listen".

In this case, both sides have plans to make a quick decision. As I said before, the attacking State of Qin has no absolute advantage in military and economy, but it has absolute advantage in politics. When the economy and military are in trouble, the political advantage of Qin comes into play.

When Zhao's food supply failed, he wanted to borrow food from Qi, but Qi refused. So the incompetent prince of Zhao wanted to make peace with Qin. Qin thought it was a good opportunity, so he deliberately entertained Zheng Zhu and created the illusion of reconciliation between Qin and Zhao for other countries. In this way, Zhao lost the diplomatic conditions to jointly attack Qin with other countries and fell into a helpless situation, which was a bad move for Zhao.

At the same time, the State of Qin spread spies widely, and sent people with treasures to Handan to buy off Zhao's ministers, alienating Lian Po. The spies and bribed people of the State of Qin spread rumors everywhere, saying that Lian Po could only defend, so he was not afraid. He will definitely surrender to Qin Jun in the end. Others say that Qin Jun is most afraid of Zhao Kuo, the son of Zhao She, the groom.

Zhao Wang was fatuous and listened to rumors, so Lian Po was dismissed as the head coach of Zhao Wang. The mothers of Lin Xiangru and Zhao Kuo strongly opposed Wang Zhao's practice, but Wang Zhao went her own way. In desperation, Zhao Kuo's mother said to the prince of Zhao, if you use Zhao Kuo as your general, please don't implicate anyone in our family once you are defeated. The prince of Zhao agreed, and Zhao Kuo went to war.