After Duke Wen of Jin ascended the throne, he straightened out internal affairs, developed production, and gradually made the Jin state stronger and stronger. He also wanted to be like Qi Huangong and be the overlord of the Central Plains.
At this time, it happened that king Xiang of Zhou, the heavenly son of the Zhou Dynasty, sent someone to ask for help. King Xiang of Zhou had a half-brother named TaiShu Dai, who united some ministers, borrowed troops from Di Guo, and seized the throne. King Xiang of Zhou fled to the State of Zheng with dozens of retinues. He issued an order asking the princes of various countries to escort him back to Luoyi. Some of the princes of the nations sent people to comfort the Son of Heaven, and some sent food, but no one was willing to send troops to fight the Di people.
Someone said to King Xiang of Zhou: "Among the princes now, only Qin and Jin have the strength to repel the Di people, and I am afraid that others will not be of any use." King Xiang sent emissaries to ask Duke Wen of Jin to escort him back to the dynasty.
Jin Wengong immediately sent troops to the east, defeated the Di people, and killed his uncle and his gang to escort Tianzi back to the capital.
Two years later, Song Chenggong, the son of Duke Xiang of Song, came to the rescue of the soldiers, saying that the Chu state sent the general Cheng Dechen to lead the five kingdoms of Chu, Chen, Cai, Zheng, and Xu to attack the Song state. The ministers all said: "The Chu state has always bullied the princes of the Central Plains, and the lord wants to help the country in difficulty and establish hegemony.
Duke Wen of Jin had long seen that in order to become the overlord of the Central Plains, he would have to defeat the State of Chu. He expanded his troops, established three armies, and went to save the Song Kingdom.
In 632 BC, the Jin army captured the two small states that were annexed to the State of Chu, the State of Cao and the State of Wei, and captured the monarchs of both countries.
King Cheng of Chu originally did not want to fight with Jin Wen, but when he heard that jin was sending troops, he immediately sent someone to order Cheng Dechen to retreat. However, Cheng Dechen thought that the Song Kingdom could be taken down sooner or later, and refused to give up halfway. He sent his generals to say to King Cheng of Chu: "Although I dare not say that I will definitely win the battle, I will also fight to the death."
King Cheng of Chu was very unhappy, and only sent a small number of troops to the command of Cheng dechen.
Cheng Dechen first sent someone to inform the Jin army, asking them to release the monarchs of Wei and Cao. However, Duke Wen of Jin secretly informed the two monarchs and promised to restore their throne, but asked them to break off diplomatic relations with the Chu state first. Cao and Wei really did as Jin Wengong wanted.
Cheng Dechen originally wanted to save these two countries, but they came first to break off relations with the Chu state. This time, he was so angry that his feet jumped straight. He shouted, "This is clearly what this old thief forced them to do." He immediately gave the order and urged the whole army to rush to the place where the Jin army was stationed.
As soon as the Chu army marched, Duke Wen of Jin immediately ordered it to retreat. Some of the generals in the Jin army could not think of it, and said: "Our commander is the monarch, and the other side is leading the troops by the courtiers.
Fox Yan explained: "To fight a war, we must first rely on reason, and we must be strong with reason. At the beginning, the king of Chu had helped the lord, and the lord promised in front of the king of Chu: If the two countries were at war, the Jin state was willing to retreat. Today's retreat is to fulfill this promise. If we lose faith in the Chu state, then we will lose money. We retreated, and if they didn't give up and press forward step by step, it was because they had lost, and it was not too late for us to fight them again. ”
The Jin army retreated ninety miles in one breath, reaching Chengpu (城濮, southwest of present-day Juancheng, Shandong), before stopping and laying out the position.
Some generals of the Chu state saw the Retreat of the Jin Army and wanted to stop the attack. However, Cheng Dechen did not agree, and chased to Chengpu step by step, facing the Jin army.
Cheng Dechen also sent someone to issue a war letter to The Duke of Jin Wen, and the wording was very arrogant. Jin Wengong also sent someone to reply: "We have never dared to forget the favor of your country, so we have given up here." Now that you are unwilling to forgive, you will have no choice but to be higher and lower on the battlefield. ”
The Great War began. Only after the exchange, the general of the Jin State used two large banners to command the army to retreat backwards. They were still dragging the fallen branches behind the chariot, and when the chariot retreated, a puff of dust rose from the ground, showing a very panicked appearance.
Cheng Dechen has always been proud and arrogant, and does not take the Jin people in his eyes. He chased straight up without hesitation, and was right in the ambush of the Jin army. The elite Chinese army of the Jin army rushed over and cut off Cheng Dechen's army. The Jin army, which had pretended to be defeated and retreated, turned back and attacked back and forth, killing the Chu army to pieces.
Duke Wen of Jin hurriedly gave the order, ordering the generals to just drive the Chu army away and not pursue and kill them anymore. Cheng Dechen returned to the middle of the road with the remnants of the defeated soldiers, and he felt that he could not answer to King Cheng of Chu, so he committed suicide.
The Jin army occupied the Chu camp. He ate the grain abandoned by the Chu army for three days before returning to China in triumph.
News of the Jin state's defeat of the Chu state reached the Zhou capital Luoyi, and both King Xiang of Zhou and his ministers believed that Jin Wen had made a great contribution. King Xiang of Zhou also personally went to Jiantu (present-day southwest of Yuanyang, Henan, in modern Jianyin Jiàn, Henan) to comfort the Jin army. Taking advantage of this opportunity, Duke Wen of Jin built a new palace for Tianzi in Jiantu, and also invited the princes of various countries to hold a general meeting and conclude a covenant. In this way, Jin Wengong became the overlord of the Central Plains.