After the Battle of Qianshi, the victorious Qi army entered the Lu State under the leadership of Bao Shuya and approached Qufu. This made Lu Zhuanggong panic. However, to his surprise, the Qi army did not come to destroy the Lu State, but to ask for hostages. Bao Shuya wrote a letter to Lu Zhuanggong, in which he hoped that Lu would execute Gongzi Jiao and send Zhaohu and Guan Zhong back to Qi. Lu Zhuanggong, who had a false alarm, faced the pressure of the Qi army, and did not think much about it, so he killed Gongzi, summoned him to hear about it, and also committed suicide. Guan Zhong was arrested by Lu Zhuang Gong and sent someone to escort him to Qi State.

In fact, Lu Zhuanggong once again fell for the Qi State. Uncle Bao and Guan Zhong have a bad relationship, how can they harm him? This idea is actually Bao Shuya's suggestion, when Qi Huan Gong planned to worship him as a minister, Bao Shuya resolutely excused himself on the grounds of lack of ability, he understood that only Guan Zhong, who is talented in the world and the world, can assist Qi Huan Gong, who is eloquent and strategic, to achieve hegemony. So he suggested that Qi Huan worship Guan Zhong as the prime minister.

Originally, Qi Huan Gong was still haunted by Guan Zhong's hatred, but under Bao Shuya's repeated recommendations, he also became interested in Guan Zhong's talent. Under the pretext of wanting to take revenge on Guan Zhong, he asked him back from the Lu State. Guan Zhong is an extremely smart person, and he naturally understands Uncle Bao's hard work. After three days of fasting, bathing, and changing clothes, Duke Qi Huan came to the post house in person and respectfully invited Guan Zhong to the palace to ask about politics, and Guan Zhong naturally pushed the boat down the river and decided to work for Duke Qi Huan.

However, the young and vigorous Qi Huan Gong did not fully follow Guan Zhong's advice at first. Because Lu Guo had always been at odds with Qi State before, and then supported Gongzi Jiao to succeed to the throne, Duke Qi Huan hated Lu State deeply. Although he won the battle of Qianshi, Qi Huan was not satisfied with the results of his self-defense counterattack. So, despite Guan Zhong's repeated dissuasion, he launched a war against Lu the following year.

It should be said that the State of Lu, which had just recovered from the Battle of Qianshi, was indeed not the opponent of the State of Qi at this time. If it fails again, it is very likely that it will collapse from now on and become a vassal of the Qi State. However, Cao Di, a low-ranking nobleman of the Lu State, changed all this, knowing that the military ability of the Duke of Lu Zhuang was not enough to command the Lu State to victory, so he volunteered to go to war.

Cao Di and Lu Zhuanggong had a very famous conversation, which is recorded in the "Zuo Chuan", the original text is as follows:

Ask: "Why fight?" The public said: "Food and clothing are safe, and if you dare to specialize, you will divide people." He said: "Xiao Hui is not gone, and the people are obedient." The public said: "Sacrifice the jade silk, and if you dare to add it, you will believe it." He said: "Little faith is not fu, and God is blessed." The public said: "Although the small and big prisons cannot be detected, they must be affectionate." He said: "Loyal people can also fight." Please follow the rules of war. ”

Cao Di denied Lu Zhuanggong's practice of relying on small favors to buy people's hearts and pray to God and Buddha for protection, but suggested that Lu Zhuanggong treat his subordinates justly, fairly, and openly, and only in this way can the morale of the whole army be boosted.

The two armies of Qi and Lu opened up a battlefield at Changlao (northeast of present-day Qufu, Shandong). According to the combat methods of the Spring and Autumn period, the two sides first beat drums to boost morale, and then sent troops to fight. Relying on the strength of the people, the Qi State took the lead in beating the drums and launched an attack. Lu Zhuang was just going to beat the drum to face the battle, but was stopped by Cao Di; Seeing that the Lu army should not fight, the Qi army had to beat the drum again, but Cao Di still ignored it; Just when the Qi army beat the third drum, the Lu army suddenly beat the drums, the two armies fought, and the Qi army was actually defeated. In this war, Cao Di took the initiative and used the principle of "one drum, then decline, and three exhaustion" to defeat the Qi army that was stronger than himself. Later generations called it the "Battle of the Long Spoon", which is also a famous example of the victory of the weak over the strong in Chinese military history.

The state of Lu was originally declining under the suppression of the state of Qi, but the battle of the long spoon revived the state of Lu. Stimulated by this battle, the Lu State took advantage of the situation to attack the Song State in an attempt to improve the status and prestige of the Lu State again. This gave Duke Qi Huan another chance to attack the state of Lu. Originally, the defeat of the Battle of Long Spoon did not make Duke Huan of Qi give up, so he once again united with the Song State, which was not on good terms with the Lu State, and jointly attacked the Qi State.

Lu Zhuanggong originally planned to hold out, but Gongzi Yan thought that he could divide and conquer and break each one. Compared with the Qi State, which had a strict military appearance and strong combat power, the Song army was full of flaws. You can break the Song army first, and the Qi army will naturally retreat. Lu Zhuanggong did not follow Gongziyan's advice, but the latter did not intend to obey the order. In order to strengthen the momentum, Gongzi Yan covered the horses with tiger skins, and secretly led the army out of the city from the south gate to attack the Song army. The Song army was really not the opponent of the morale-boosting Lu army, and was defeated by the Lu army in Chengqiu. Seeing this, Qi had no choice but to retreat. In the second year, in order to take revenge, the Song State once again raised troops to attack Lu, but unfortunately the Song State with the help of the Qi State could not defeat the Lu State, and now it is not an opponent to send troops alone. The two armies fought at Yudi, and the Lu State first lined up the formation, and launched an attack before the Song army could finish the formation, defeating the Song army again.

The Song State was involved in the dispute of Qilu for no reason, and lost consecutive battles, which also triggered another civil strife in the Song State. It turned out that in the battle of Chengqiu, Nangong Changwan, a fierce general of the Song State, was shot by Lu Zhuang Gong with a golden servant and an arrow, and was captured alive, and was later released and returned to China under the repeated pleas of the Song State. When greeting Nangong Changwan, Song Mingong said casually: Because Nangong became a prisoner of the Lu State, he will not respect Nangong in the future. This was originally an unintentional joke, but unexpectedly, it cost Song Mingong a life.

Nangong Changwan was humiliated by the Lu State, and he was already resentful, but he was so ridiculed by the monarch that he naturally held a grudge, so he decided to rebel. In the first year of King Xi of Zhou (682 BC), Nangong Changwan launched a rebellion, first killing Song Min Gong in Mengze, and then killing Dazai Huadu near the East Palace, and established Gongzi You as the monarch. The sons of the Song State fled to the Cao State one after another, and quickly organized an army to try to defeat Nangong Changwan. Uncle Xiao Daxin and other clansmen in the office borrowed troops from Cao Guo and killed them back to the Song State, first killed Nangong Niu, the clansman of Nangong Changwan, and then entered the capital to kill Gongzi You, and set up Gongzi Yu, who fled to Bodi, as the monarch of the country, for Song Huan. Nangong Changwan and another of his subordinates fled to Chen and Wei in a hurry. Song Guo immediately negotiated with Chen and Wei, hoping to send the two back. At first, Wei Guo wanted to shelter Mengyu, but under the persuasion of the doctor Shi Qizi, he still handed over Mengyu. And Chen Guo, under the temptation of the financial gifts promised by the Song State, was also happy to be a favor, so he drunk Nangong Changwan and sent him back to the Song Kingdom wrapped in cowhide. Eventually, both were put to death.

After this civil strife, the Song State weakened again and was unable to compete with the surrounding countries. At the same time, Duke Huan of Qi also realized that with the current national strength of Qi, he could not dominate the princes, so he turned his attention to the domestic and began the reform of the political and economic system under the auspices of Guan Zhong.

The battle with the Lu State did not take any advantage, which was undoubtedly a blow to the Duke of Qi Huan at the beginning of his reign. But Qi Huan Gong is worthy of a generation of Ming Jun, he did not flinch because of temporary setbacks, but wisely realized that for the Qi State that had just recovered from civil strife, if he wanted to fight for hegemony, he still had to start from internal affairs. So he appointed Guan Zhong as secretary of state and set off a comprehensive reform in the state of Qi.

With the eastward migration of King Ping and the decline of the status of the Zhou royal family, the patriarchal system has de facto collapsed, so the household registration management system with the patriarchal system as the core also needs to be reformed accordingly. During the Spring and Autumn Period, each vassal state was divided into a country (within the national capital) and a wild (outside the national capital). Guan Zhong divided the area within the national capital into 21 townships, which were inhabited by industry, commerce and scholars, of which 3 were industrial townships, 3 Shang townships and 15 Shi townships, and Shi townships were managed by the two nobles of Qi Huan Gong and Gaozi and Guozi. Under the township (2,000 households), there are Lian (200 households), Li (50 households), and rail (5 households).

The subordinate relationship is: five for the track, ten for the li, four for the company, ten for the township, respectively by the track chief, the division, the company commander, the township (or the township doctor) management. The area outside the national capital is 5 genera (districts), which are the residence of farmers. There are counties (9,000), townships (3,000), pawns (300), and yi (30). The subordinate relationship is: 30 families are yi, and the chief is called yi yousi; 10 Yi is a pawn, and the chief is called a pawn; 10 Pawn is a township, the prefect is called the township marshal, 3 townships are the county, the prefect is called the county marshal, 10 counties are subordinate, the prefect is called the doctor and the chief, and the five doctors of the imperial court are directly managed.

This system, known as the "Sanguo Wu" system, abolished the feudal system of aristocratic fiefdom and replaced it with a system similar to that of the later county system. It is not only a basic structure of daily administration, which is conducive to personnel management and tax collection, but also directly combined with the military service system and played an important role in the war for hegemony of the Qi State. Because the system of "participating in the fruit and contempt" uses a system of layered management such as rail, li, company, and township, it can easily be transformed into a military system in wartime.

According to Guan Zhong's design, among the 21 townships under the national capital, in addition to the six industrial and commercial townships, there are still 15 Shi townships. Each family sent a strong man to join the army, and there were five soldiers in one track; And so on, fifty families in one mile, fifty soldiers; a company of 200 families, with 200 soldiers; There are 2,000 households in one township, 2,000 soldiers, 10,000 households in five townships, 10,000 soldiers, 10,000 soldiers are organized into an army, and there are 30,000 households in fifteen townships, there are 30,000 soldiers, which can be organized into three armies.

In addition, Guan Zhong also improved the source of soldiers. During the Spring and Autumn Period, the kind of mercenaries who took war as their profession in later generations did not appear, and all countries generally implemented the compulsory military service system, that is to say, the common people who lived and worked in peace and contentment on weekdays became soldiers who charged into battle during the war. Based on this situation, Guan Zhong decided to use the "shi" class as the main source of Qi's army.

When it comes to "scholars", people often tend to think of Confucian scholars and talents who are powerless and can only dance and write, in fact, that was a long time later, and the "scholars" in the Spring and Autumn Period are far from this image, if you must find a reference, they are closer to the "knights" of the Middle Ages in Western Europe. During the Spring and Autumn Period, scholars needed to master the six arts, namely etiquette, music, archery, royalty, calligraphy, and mathematics. Therefore, compared with the peasant, industrial, and commercial classes, their quality is relatively higher.

As a result, the personal quality of the Qi army was greatly improved, and its combat effectiveness rose sharply; Not only that, the military system is closely linked to the day-to-day administrative structure, and can be seamlessly switched at any time, which makes the military structure more standardized, greatly improves the combat efficiency of the army, and also reduces the burden on the people.

In addition, in order to improve the actual combat capability of the army, Guan Zhong also devised an effective training method: stipulating that the army should go out hunting every season, on the one hand, to familiarize the soldiers with combat skills, and on the other hand, it also has the effect of eliminating pests and maintaining public order. In addition, Guan Zhong also demanded that the people of the Shixiang should not move casually, and to "sacrifice the same blessings, die and mourn the same", and love each other from generation to generation, so that the soldiers can "live together for pleasure, die for the same mourning, the same code for solidity, and the same strength for war", even if they fight at night, they can distinguish friend and foe from their voices, and when they fight during the day, they can recognize their identities as long as they see their faces.

Of course, in addition to improving the combat effectiveness of the army, the strength of the army also requires advanced weapons. The iron-smelting technology that emerged in the Spring and Autumn period was of great significance to agricultural tools and weapons. But how can we quickly concentrate iron raw materials? Guan Zhong came up with a "lenient atonement": he announced that the criminals of Qi could offset their punishments by paying weapons, armor, and even ores. If a felony is committed, he may be atoned for with money or goods equal to the halberd of a chariot; Misdemeanors can be atonemented with money or goods equivalent to the halberd; Petty sins can be atoned for with copper and iron. This system not only solves the problem of the source of armaments, but also expands the state's fiscal revenue, eases domestic contradictions, and achieves twice the result with half the effort.

In addition to these reforms, Guan Zhong also made some changes to the old talent selection system for determining official positions based on blood relationship, he himself is a son of a dilapidated aristocratic family, and naturally knows that the long-standing selection system of heroes based on family rank has long been unable to keep up with the changes of the times.

First of all, he selflessly recommended the "Five Masters" to the Duke of Qi Huan: Xi Peng, who was good at arguing with Ming etiquette, Ning Yue, who was familiar with agricultural affairs, Wang Yucheng, who was brave and good at fighting, Bin Suwu, who was honest and upright, and Dong Guoya, who was outspoken, all of whom held important positions in the Qi State. Later, a new election system was formulated, stipulating that all talents were recommended by the township chief and subordinate doctors, and the important ministers of the imperial court were evaluated, and the Duke Huan personally consulted and questioned, which was called the "three selections". If local officials bury and suppress talents, they will be punished with the crimes of "concealing the virtuous" and "concealing the light".

Not only that, Guan Zhong also suggested that Qi Huan Gong vigorously recruit talents from other countries, send eighty "travelers", bring more gold and silver property, wear silk and satin, drive a BMW incense car, tour the Quartet, and immediately invite the hermits to return to Qi when they see the hermits. For a time, Qi was full of talents and guests.

Through political and military reforms, Qi has a relatively advanced political system and a strong combat army, but to maintain the operation of the state apparatus, it also needs to rely on strong economic strength, so Guan Zhong has also carried out a series of reforms in the economy.