Chapter 10: Chu's invasion of Ba and Han, Qin and Shu form an alliance, encountering the armies of the three kingdoms of Han.

  In the spring of 325 BC (the fourth year of Chu Huai Wang and the thirteenth year of Qin Huiwen Gong, the first year of Qin Huiwen Wang), this was the year when Qin Huiwen Wang began to call himself king and prepare to compete for the Central Plains. Chu Huai Wang ordered Zhaoyang to lead a large army northward, deploying troops in Xiangyang, Nanyang, Fang, and Ye, while personally leading 200,000 elite soldiers with Zhaoyu out of Dangyang, advancing towards Shangyong and Fagong (Hanzhong), claiming to punish the State of Shu for its unrighteous actions in invading Chu during the mourning period in 327 BC (the second year of Chu Huai Wang). Why did Chu Huai Wang have to go to Fagong (Hanzhong) to attack the State of Shu? It turned out that Hanzhong (now southwestern Shaanxi Province, including the area around present-day Hanzhong City) was part of the territory of the State of Shu at that time and was a necessary passage from Guanzhong to the Sichuan Basin. During the Zhou Dynasty, this area was known as Fagong, with its territory stretching from Lüeyang County to Chenggu County. Therefore, some historical books also referred to it as Fagong. In 770 BC, due to the invasion of the Di and Quanrong tribes, a group of people from Zheng (now Hua County) fled to the southern bank of the Han River in Hanzhong and settled there, which was then called Nanzheng. Later, when the Qin state expanded its territory to eastern Shaanxi, the area around Hua County became part of the Qin state, and since 451 BC, the Qin people began building a city in Nanzheng, referring to Hanzhong as their southern Zheng. Later on, after Fagong was defeated by Shu, the territory of Fagong (Hanzhong) became part of the State of Shu. The "Huayang Guo Zhi: Shu Ji" records: "During the reign of King Xuan of Zhou, the Marquis of Shu had control over Fagong."

  The Marquis of Shu heard that the King of Chu was leading an army of 200,000 to invade Han (Hanzhong) and avenge his grievances. He was so anxious that he could not eat or sleep. On one hand, he led the armies of Shu to rush to Han (Hanzhong), and on the other hand, he sent a letter to King Huiwen of Qin asking for help.

  King Huiwen of Qin received the Marquis of Shu's letter seeking help and immediately summoned his civil and military officials to discuss the matter. He said: "Now that the King of Chu is leading an army of 200,000 into Han (Hanzhong) to avenge his grievances, the situation is urgent and cannot be stopped. The Marquis of Shu has come to me for help, what do you think? Should we rescue him or not?"

  A minister reported: "Han (Hanzhong) is a natural pasture and granary, it is an important strategic location for Qin's southward expansion into Ba and Shu. If the king does not send troops to rescue Shu, the army of Shu will be no match for the Chu army, and within one or two months, the entire Han (Hanzhong) region will be occupied by the Chu army. Once the Chu army occupies Han (Hanzhong), they will march southward to attack Shu, and the entire state of Shu will fall to Chu. By then, it will be even more difficult for the king to plot against Ba and Shu. Moreover, once the opportunity is ripe, the Chu army will march west from Han (Hanzhong) to attack Qin's territory, and the situation will become very dangerous."

  King Huiwen of Qin said: "Your words are extremely wise, I also have this concern. However, since the time of King Wei of Chu, their military has been strong, and now that the King of Chu is leading a large army, it is difficult to stop them. If I lead a large army personally, there will inevitably be a life-and-death struggle, and at that time, the king of Wei will lead his army to attack our western border, and Qin's military situation will become precarious."

  A minister said: "The king does not need to worry about this. Currently, the Shu army still has over 100,000 soldiers, the king can send 100,000 elite troops, together with the Shu army of 200,000, we can defeat the Chu army. The Chu army may have marched from Fangshan to Ankang for three hundred miles, but this region is all mountainous terrain, and it is not convenient to transport grain and fodder. Therefore, the Chu army cannot stay in Han (Hanzhong) for long, as long as we confront them, after some time, the Chu army's grain and fodder will be exhausted, they will inevitably retreat, and then we can take advantage of the situation to attack and defeat them."

  King Huiwen of Qin said: "Good!" He immediately ordered Sima Cuo to mobilize 100,000 elite troops (30,000 cavalry and 70,000 infantry), to follow him to Han (Hanzhong) to confront the Chu army.

  In the spring of 325 BC, in the third month (the fourth year of Chu Huai Wang), Chu Huai Wang led the Chu army out of An Kang (now Ankang City) and encountered the allied forces of Qin and Shu, numbering several hundred thousand, at Han Yin (now Hanyin County). The two sides formed their cavalry and infantry into arrays on a flat plain. Chu Huai Wang rode forward to face Qin Hui Wen Wang and said: "Are you not King Hui Wen?" Qin Hui Wen Wang replied politely: "Indeed it is I, and you are King Huai, aren't you? You truly have an extraordinary bearing, even more majestic than your father, King Wei." Chu Huai Wang said: "It is I. My late father told me that you were a man who understood reason, and that our two families had a close relationship through marriage. Why do you repeatedly cause trouble for Chu?" Qin Hui Wen Wang replied: "I did not intentionally cause trouble for Chu. Shu was a neighbor of Qin's, and when they came to us for help in their time of need, how could I refuse? It is only right that relatives help each other and neighbors assist one another. You should understand this principle! Moreover, the queen mother of my son is a princess from Chu; how could I not know about it?" Chu Huai Wang said: "Shu took advantage of our country's mourning period to launch an attack on us, which was extremely arrogant." Qin Hui Wen Wang said: "That was indeed wrong of Shu. However, you have already vented your anger, and the cities of Zi Yang and Suining in Shu have already been occupied by you. Why do you not spare them? Are you determined to destroy them before you will stop?" He then beckoned to the Marquis of Shu to come forward. The Marquis of Shu was afraid because he had been defeated by Chu Huai Wang previously and did not dare to approach him. Qin Hui Wen Wang said: "What are you afraid of? I, the king, am here with my trusted general, Sima Cuo." Only then did the Marquis of Shu ride forward, trembling as he spoke: "King Huai of Chu! Last time it was I who was in the wrong. Please forgive me and spare me this time!" Qin Hui Wen Wang said: "Is that not settled? Let us value harmony between our two sides." Chu Huai Wang listened to this and smiled coldly, saying: "A great army has been mobilized, involving the lives and property of several hundred thousand people. Can it be dispelled by a few flowery words?" The Marquis of Shu said: "What do you want to do then?" Chu Huai Wang replied: "We can stop fighting, but Shu must compensate us for our military expenses." The Marquis of Shu asked: "How much compensation do you want?" Chu Huai Wang said: "Cede the region of Bo Han (Hanzhong) as reparation for our military expenses." Qin Hui Wen Wang said: "Are you not coercing them?" Chu Huai Wang sternly replied: "This is a matter between Chu and Shu; what business is it of yours? You, a third party, are meddling in this affair. I advise you to mind your own business and leave!" Qin Hui Wen Wang said: "I will definitely intervene in this matter today." Chu Huai Wang coldly laughed and said: "We shall see if you have the ability to do so."