Qi and Zheng became close allies as early as the reigns of Duke Qi and Duke Zheng Zhuang; Qi Guo helped Zheng Guo against Song and Lu, and Zheng Guo helped Qi Guo against Ji Guo.

After the death of Zheng Zhuanggong, Zheng Guo had more than ten years of civil strife, and the regime changed several times, and each change was promoted by the black hand of foreign forces. As a result, there is a great deal of uncertainty in the relationship between Qi and Zheng.

In the end, Zheng Ligong killed Ziyi with the help of the power of the Chu State, realizing the restoration and reunification of the country. But Zheng Ligong is a realistic utilitarian, and he immediately left his former benefactor behind and devoted himself to the unfinished business of his late father, Zhuang Gong.

Later, when the Eastern Zhou Dynasty had a rebellion of five doctors, Zheng Ligong went out to study King Qin, he killed the prince and sent King Zhou Hui back to the throne; Zheng Ligong's outstanding exploits made him the most famous figure in China for a time, and the limelight even overshadowed that of Qi Huangong.

But Zheng Ligong died before he could establish a greater career. His successor, Zheng Wengong, was a squeamish bag who had been kept in captivity in a rich and golden house since he was a child, and after he ascended the throne, he became the most depraved person in the whole Zheng Kingdom. Although Zheng Wengong has not yet shown the characteristics of a tyrant, his short-sightedness, paranoia, arbitrariness, and capriciousness have led Zheng Guo on an unhindered path to decadence.

Eight years ago (the twenty-eighth year of the reign of Lu Zhuanggong), the state of Chu ordered Yin Ziyuan to lead a chariot of 600 to easily drive into the south gate of Xinzheng, and almost killed the monarch and ministers of Zheng Guo. That incident greatly stimulated the nerves of Zheng Guoren, and even Zheng Wengong had to become serious and regard the establishment and improvement of the national early warning mechanism and the construction of the defense system as a top priority.

Later, through a series of victories in the northern Rongdi war, the state of Qi firmly controlled the princes of the Central Plains in their own hands; The prestige of the state of Qi spread far and wide to the Huai and Han dynasties, greatly covering the reputation of the state of Chu, and the small states such as Jiang and Huang in the Huai River valley did not hesitate to betray the old lord and turned to the state of Qi.

The national strength of the state of Chu declined rapidly during the period when Wang Zishan was in power, and Wang Zishan emptied the wealth of the entire country, and the country changed from a Jianghan giant to a weak tuberculosis ghost; So much so that after the Ao clan cleared Wang Zishan's forces, he had to scatter his family wealth to save people's livelihood and restore the country's economy.

It has been a full five years since Ruo Ao's destruction of Wang Zishan to the Chu State's attack on Zheng last year. The country quickly regained order and vitality under the leadership of the young and promising King Chu Cheng and the young and powerful Ling Yin Ziwen.

When the Chu people turned their attention from home to abroad again, the Chu people were saddened to find that the alliance with the Chu State as the core had existed in name only; The loyalty of members to the alliance leader gradually weakened with the weakness of each country and the proximity to the Chu state; The minor princes did not serve as kings, they either hooked up with the Qi state, or set up their own mountains.

The people of Chu thought that if they didn't show their strong muscles to the princes, they might even have to run to Linzi and smile at Qi Huan, and as a result, the above-mentioned incident of cutting Zheng happened.

However, the revival of the state of Chu not only caused panic among the smaller states, but also intensified the speed at which some countries defected to the state of Qi. In the second year of the reign of Lu Xi (658 BC), secret envoys from Jiang (southwest of present-day Xixian County, Henan) and Huangguo (northwest of present-day Huangchuan, Henan) came to Linzi and asked to join the Huaxia Alliance.

Both countries belong to the country of the surname Ying, and both were built in the early Xia Dynasty. When Qi Huan complacent told the doctors about the secret belief and regarded the submission of the two countries as one of his many great achievements, Guan Zhong expressed cautious optimism and great apprehension.

Guan Zhong said: "Jiang and Huang are closer to Chu and farther than Qi. Jiang and Huang are to Chu like Lu and Song are to Qi, and Chu can't give up Jiang and Huang is like Qi can't give up Lu and Song. Once Chu is defeated and Jianghuang, will Qi save or not? Save, it's too late; If you don't save it, where is the face of the overlord? The minister thought that it was better to decline the kindness of the two countries and concentrate on the management of the Central Plains. ”

Duke Qi Huan shook his stubborn head and said disapprerovingly: "With the glory of my Great Qi Kingdom and the grace of the widow, the king of Chu will one day go to Linzi to bow down to the widow; At that time, the master would not be worried about the annexation of Jianghuang by the Chu State. ”

Immediately there was a chorus of flattery in the court, and the bill was passed in the midst of the flattery of the crowd.

In the autumn, Duke Huan of Qi held a grand alliance meeting in Guan (present-day southern Cao County, Shandong). In addition to the Marquis of Qi and the Duke of Song, there were also monarchs of the Jiang and Huang kingdoms. The princes generally believed that the Qi people held this alliance meeting with great fanfare was revenge for the Chu state's attack on Zheng last year.

However, as Guan Zhong said, although the two countries took refuge in the Qi State, they could not be effectively protected. The Huang State was destroyed by the Chu State nine years later; The Jiang State stood firm for twenty-six years, and when it was destroyed by the Chu State, the Chinese overlord had been replaced by the Qi State to the Jin State.

The arrogance of the Qi people caused a strong backlash from the Chu State. In the winter of this year, the state of Chu invaded the state of Zheng again; The two armies fought a battle on the outskirts of Xinzheng, the Chu army defeated the Zheng army, and the Chu general Douzhang captured the opposing commander, Dan Bo.

Chu's revenge, in turn, provoked the anger of the Qi people, and Duke Huan of Qi decided to teach the arrogant little viscount a good lesson (the Chinese princes did not recognize the prince of Chu and still referred to him as "Chu Zi").

In the following year (657 BC), Duke Huan of Qi convened a general meeting of princes in Yanggu, the main content of which was to discuss how to deal with the northern expansion of Chu.

The princes generally believed that it was too difficult to directly crusade against the state of Chu: first, because of the strength of the enemy; second, because the road is long and difficult, and the people of the Central Plains are not familiar with the geographical environment; third, because of the fear that the expeditionary force would not be able to adapt to the scorching heat of the south; Fourth, because in the face of such a giant, the princes felt that they couldn't speak.

In the end, the participants reached an agreement: they could meet the Chu army in the Central Plains, but they would never attack Chu in the south.

In the autumn of that year, the Chu army attacked Zheng for the third year in a row. The army of Chu came to the city of Xinzheng, but the Chinese reinforcements were delayed. Zheng Wengong was fed up with the endless harassment of the Chu people, and he was also tired of the arrogant rhetoric of the Qi people, he said: "Qi Xiaobai can't do anything but talk empty words!" He was powerless to even save his allies, but he made a lot of nonsense, saying that he would go straight to Yingdu and divide Chu State into a county of Qi State! Now, Chu Zi and his army are blocking the gate of Xinzheng, but where is Qi Xiaobai?

"If the people of Qi can catch Chu Zi in the Central Plains, do they still need to mobilize the army to move south? If Qi Hou didn't even want such a rare opportunity to verify his promise, what hope did the widow have for him? In terms of kinship, Qi Hou has nothing to do with the widow, but Chu Zi is the widow's brother-in-law! It's so stupid to be a widow, why should you abandon your in-laws and trust an outsider? After saying these words, he prepared to negotiate peace with the state of Chu.