In the ten years from the time Zheng Mugong took the initiative to defect to Chu (the first year of Lu Xuangong) to the eleventh year of Lu Xuangong (the year before the outbreak of the Battle of Yi), Zheng was attacked almost every year by the Jin or Chu states.

In the winter of the ninth year of Lu Xuangong, the king of Chuzhuang attacked Zheng, and Yin Que led the Jin division to save Zheng. At that time, the Chu army focused mainly on the Jin people, but neglected the defense of the Zheng people; As a result, the young and vigorous Zheng Xianggong personally led the army to battle and defeated the Chu army in Liudi.

Zheng Guoren was ecstatic because Zheng people had won an almost impossible victory. But Ziliang looked worried. He said: "The victory over Chu is the beginning of the disaster that Zheng suffers, what can you rejoice about? Our death is near, and you are gloating! ”

In the winter of the tenth year of Lu Xuangong, the king of Chuzhuang attacked Zheng again, and the scholars would lead the Jin division and the princes to save Zheng. The two sides encountered in Yingbei, the Central Plains princes had an advantage in military strength, and the Chu division did not dare to confront each other head-on, so they pulled out the camp and withdrew. The coalition forces drove the enemy out of the Zheng border all the way, and each sent some troops to help the Zheng people defend Xinzheng.

In the spring of the eleventh year of Lu Xuangong, the king of Chu Zhuang attacked Zheng for the third time, and the Zheng people had been overwhelmed by the endless invasion of the Chu people, Ziliang said: "Jin and Chu do not subdue people with virtue but only fight by force, and Zheng Guo only needs to obey those who come." Jin and Chu have no faith, why should we keep our promises? As a result, the Zheng people concluded an alliance with the Chu people in Chenling.

However, in the winter of that year, the Jin people attacked Zheng again, and the Zheng people fell to the side of the Jin State when the blood of the (Chenling Alliance) was not dry.

King Chuzhuang was enraged by the capriciousness of the Zheng people, and he was eager to fly in front of Zheng Xianggong and knock out his brain.

The ministers also showed great emotion, and shouted in unison: "There can be no more benevolent policies towards Zheng Guo!" When we threaten, they give in; They only ask for and, and we will allow it. When the army returned home, the Zheng people tore up the covenant and fell to the Jin state, and all we held in our hands was a bundle of fire-making leads.

"The Chu State mobilized the people, labored the people and lost money, while the Zheng Guoren were unscathed, playing with the Chu State in the palm of their hands. It seems that Zheng Guo can't be intimidated but can only be subdued. This time, Zheng Guo must be beaten, and Gongzi Qijian and other prominent nobles must be obtained as hostages, otherwise Zheng Guo will never serve Chu Guo with all his heart! ”

This proposal was in line with the idea of the king of Chu Zhuang, and the people of Chu immediately began to prepare for a war of unprecedented scale against Zheng.

Zizhong has some friendship with Dr. Zheng Guoshi, and Zizhong gradually discovers that although the other party has thick eyebrows and big eyes and looks righteous, his stomach is actually full of bad water. There was nothing in Ishise's mind that could not be betrayed, so Zizhong wrote a secret letter to Ishise, asking him to provide him with information about Jeong's defense, and promising to give him great benefits afterwards.

Since Zizhong was vague about "benefits" in the letter, Shi Zhi first politely rejected Zizhong's "good intentions" in the letter, and then talked rambly about his noble origin, prominent position, great ability, and incomparable loyalty, until finally he unashamedly set out his conditions for treason - it turned out that he wanted to use the power of Chu to overthrow Zheng Xianggong, set up Gongzi Yuchen as king, and wanted to get the status of Shangqing from the coup d'état.

Zi replied that everything was possible, as long as he could do what Chu asked for, Chu would be able to meet his requirements. Since then, Shi Zhi has played the role of a spy for the Chu State, and has passed the secrets of the Zheng State to the Chu State without reservation and in a steady stream.

Zheng Guo began to prepare for war with the whole people, and people repaired the city walls, built fortifications, dug wells, hoarded grain, forage, and wood, and made various weapons in large quantities.

In the spring of the twelfth year of Lu Xuangong (BC597), the three armies of Chu were raised: Shen Yin will be the middle army, Zi will be the left army, Zizhong will be the right army, Bao Ai Lie, Pan Yu, and Wu Shen will go out with the king of Chu Zhuang, and a large number of auxiliary troops from Shanrong and Huaiyi will accompany them.

The Zheng dug two more wide and deep trenches outside the moat, and strong fortresses were built on the inside of the trenches. However, the Zheng people did not have enough troops on the outer defense line, and as a result, the defense line was quickly broken through, and the Zheng people had to retreat to the city. The whole army of Chu immediately pressed on and surrounded Xinzheng.

The Chu army filled in the moat, and then used various weapons to storm the city. The Zheng people were undaunted and stuck to the city wall to fight the invading enemy. However, the Chu army was good at attacking cities, while the Zheng army was not good at defending cities (the Zheng army was also good at attacking); The enemy's attacks continued day and night, and they became more and more intense. Zheng Ren felt more and more pressure, so he divined the future.

Seeking peace is unlucky; Bu Lin in the palace and the streets and alleys out of the car, auspicious. "Presence in the Great Palace" is to cry bitterly in the Taimiao, and the meaning of this ritual is now unclear, but it is probably an act of mourning for the imminent death of the country and inspiring the strong determination of the people of the country to share the same hatred and hatred.

Zheng Xianggong led the ministers into the temple en masse, and after the temple ceremony, he let out a cry of sorrow; At the same time, all the chariots in the city were driven out and displayed in the streets, and the people of the country also wept, and the soldiers who defended the city wept on the city walls.

Xinzheng suddenly turned into a sea of bitter tears, and there was no one whose grief was not from the heart, and no one's anger that was not truly aroused. After that, Zheng Xianggong walked out of the temple and delivered a speech to the Chinese people gathered in the square, calling on the people to unite and swear to defend their homeland.

At midnight that day, a death squad of the Zheng people broke through the city gates to attack the Chu army, and the death squad inflicted considerable casualties on the enemy and burned a large number of siege engines and trebuchets. The walls were crowded with all sorts of people, brandishing torches, beating drums, gongs, basins, and everything that made a sound, and shouting in solidarity with the warriors in terrorizing the enemy.

Chu Jun couldn't figure out Zheng Ren's intentions, so he didn't dare to act rashly. In fact, the Chu army could completely annihilate the enemy. Since the Chu army did not attack, the death squad returned at a small price.

The Chu army retreated ten miles to continue building siege weapons, while the Zheng people took the opportunity to repair the broken city walls. When the two sides finished their work, the Chu army surrounded them again.

As early as when the Chu army entered the country, the Zheng people were looking forward to the early arrival of Jin reinforcements; But until the fall of Xinzheng, people did not see half a figure.