In 5 14 BC, Lu Wen ascended the throne of Wu State, and appointed Wu Zixu, a former aristocrat of Chu State who fled to Wu State, and Sun Wu of Qi State to reform internal affairs, expand troops and strengthen combat readiness. And formulated the strategic policy of "breaking the west and strengthening Chu, uniting gold in the north and serving Vietnam in the south" At that time, the territory of the State of Yue, which occupied the northern part of Zhejiang, was narrow, sparsely populated, and its economic and cultural development was relatively backward. In order to unite the State of Yue to check and balance the State of Wu, Chu actively supported the King of Yue and Yun Chang, thus making the power of the State of Yue grow rapidly.
In 5 10 BC, in order to achieve the strategic goal of "serving the Vietnamese from the south", Wu began to attack the state of Yue, and the war between the two countries began. Both sides have come and gone, and a long-term tug-of-war has begun. In 506 BC, He Lv led an army to attack Chu. In the spring of the following year, Yun often took advantage of the emptiness of Wu State to send troops to attack Suzhou, the capital of Wu State. The prince of Wu hurriedly withdrew his troops to save him, so that Chang knew that he could not be defeated, so he took the initiative to withdraw his troops and returned them after the robbery.
In 496 BC, Yun Chang died of illness and his son Gou Jian succeeded to the throne. He Lv, the king of Wu, took advantage of the unstable domestic political situation shortly after Gou Jian ascended the throne and led an army to attack Vietnam. The two sides lined up in Meihua (now southwest of Jiaxing County, Zhejiang Province). Seeing Wu Junrong's neatness, Gou Jian organized death squads to attack several times in a row, but they were all repelled by Wu Jun. In this case, Gou Jian forced prisoners who committed capital crimes to line up in three columns, walked to Wu Jun with swords and committed suicide together. Wu Jun soldiers were stunned by this crazy move, and flocked to watch, and Wu Jun was in chaos. The Vietnamese army took the opportunity to launch a surprise attack and defeat Wu Jun, and He Lv himself died because of his injuries. Before he died, he repeatedly reminded his son Focha: "If you avenge me, don't forget it!"
After Fu Cha acceded to the throne, he always kept in mind the revenge of killing his father, inspired himself with the last words of "Don't forget to cross over", trained day and night, actively prepared for war, and prepared to send troops to attack. In the spring of 494 BC, Gou Jian, the king of Yue, learned that Fu Cha was going to attack Yue, but he didn't listen to Fan Li's advice. In the case of inadequate preparation, he decided to take the initiative to attack Wu. Fu Cha sent all the elite soldiers of Wu to meet Yu Fujiao (now southwest of Suzhou, Jiangsu). Under the slogan of "Don't forget Vietnam", Wu Jun fought bravely, and the Vietnamese army lost ground and suffered heavy losses, leaving only 5,000 people to retreat to Kuaiji Mountain. Wu Jun pursued the victory, occupied Huiji Mountain in Du Yue, and then surrounded Huiji Mountain. At the critical moment of life and death, the doctor of Yue put forward the idea of bearing the burden of humiliation and perfection, and advocated humility and surrender to Wu. Otherwise, Gou Jian will personally go to Wu as a hostage. Gou Jian adopted this suggestion, prepared to fight to the death, sent Wen Zi to make peace with the prince of Wu, bribed Wu Taizai with beauty and treasure, asked him to mediate, and persuaded Fu Cha to allow Yue to be a vassal of Wu. If Xu announces that Wu is not allowed, Yue will cross the rubicon and fight Wu to the end.
Wu Zixu of Wu believes that "if you don't destroy Vietnam today, you will regret it in the future". It is better to fight for the Central Plains than to destroy Vietnam. Seeing the ambition of destroying Wu hidden behind the courtesy of the monarch and minister of Yue, he insisted on completely destroying Yue. Otherwise, it will lead the tiger back to the mountain and make great contributions. However, Fu Cha still does not forget his father's dream of the Central Plains at this time, thinking that since Yue surrendered, he would exist in name only and have been avenged. Therefore, he promised to negotiate peace with Yue and lead his army back to China. Wu Zixu's proposal was rejected because Fu Cha was short-sighted.
After this battle, the strength of Yue was greatly weakened. In order to reassure people, Gou Jian wrote a letter to himself:
"I don't know that my strength is insufficient, but I bear a grudge against a big country that exposes the bones of the people of the Central Plains. This is my sin, and I ask you more. "
He also ordered "to bury the dead, ask the injured, keep healthy, worry, celebrate, send, welcome, eliminate the evil of the people and make up for the shortcomings of the people."
Then, the domestic affairs were entrusted to the doctor, who took others to Wu to be slaves of Fu Cha. Gou Jian endured humiliation in Wu, and finally won the trust of Fu Cha. This is the origin of "serving a salary and tasting courage", and it is also the direct reason why Gou Jian is determined to counterattack Fu Cha. Three years later, Gou Jian was released and returned to China. After Gou Jian returned to China, he was determined to avenge himself, restore the country and destroy Wu. He began a series of reforms to improve people's livelihood and strengthen national strength:
Strive for people's hearts, select talents and appoint people, let Wen Zi govern the government, Fan Li rectify the army, and set up a recruiting hall to accept talents from all walks of life. Reform internal affairs, reduce penalties, reduce taxes, reclaim wasteland, develop production, encourage fertility and increase population. Militarily, build a city and build a profile, repair the capital destroyed by the war, train the army, reward and punish severely, and expand the source of troops. In foreign policy, it pursues the policy of "uniting with the Communist Party, being pro-Chu, paying a lot of money and being lenient with Wu". Constantly give generous gifts to Fu Cha to show loyalty and obedience, so as to eliminate his vigilance against the state of Yue; Give him beautiful women and girls, so that he can indulge in womanizing and distract his energy; Bribing Chen Wu to win their sympathy and help; And alienate the interior of Wu and provoke discord among ministers; Destroy Wu's economy and buy Wu's grain at a high price, which makes its internal food prices soar and causes supply difficulties; Collecting excellent materials and selecting skilled craftsmen to give them to Fucha will promote its construction and consume manpower and material resources. The above measures have achieved remarkable results, strengthened themselves and weakened the enemy. The strength of Yue has been greatly enhanced, and it is only a matter of time before he sends his troops to attack Wu.
While the State of Yue is wholeheartedly making great efforts to cure the disease, and is ready to "avenge", the State of Wu is becoming increasingly corrupt. Fuxi was arrogant because of his victory, extravagant and lustful, and militaristic. In order to build Gusutai, a lot of manpower and material resources were mobilized, and the stone met on it day and night. At the same time, he was eager to threaten Qi Jin by force and dominate the Central Plains. The attack on Chen in 489 BC and Lu in the following year shocked the small countries nearby and opened the way for the north to enter the Central Plains. Fu Cha also recruited a large number of migrant workers to build Seoul, as a base for going northward, digging ditches, communicating with Jianghuai and facilitating military transportation. In order to induce Wu to enter the Central Plains in the north, make enemies with Jin and Qi and Chu, and create opportunities to attack Wu by taking advantage of his weakness, Gou Jian attached great importance to Fu Cha, and asked him to lead tens of thousands of civilian workers to help Wu dig the Han ditch, so as to push Fu Cha northward.
In 484 BC, Fu Cha heard that Qi Jinggong was dead, and decided to go north to cut Qi, unite with Lu Army and defeat Qi Army. After the war, Fu Cha became even more arrogant, thinking that the hegemony of the Central Plains could be realized by finally conquering the State of Jin, so he agreed that Jin Dinggong and the governors of other countries would meet in Huangchi (now southwest of Fengqiu, Henan) on July 7, 482 BC. Gou Jian's dream opportunity has finally come. It paid off. Under the banner of "revenge", on June 12, 482 BC, he mobilized Vietnamese soldiers to attack Gusu in two ways, and Fu Cha, who was far away in Huangchi, barely became the overlord, realizing the wishes of two generations. However, because the news of the loss of Gusu had been leaked and the morale of the army was shaken, Fu Cha felt uncertain about fighting back against the Vietnamese army, so he sent someone to make peace with the Vietnamese army. Gou Jian also allowed peace talks and withdrew his troops to return home because of his lack of strength. After Fuxi made peace with Vietnam, due to years of war, production was greatly damaged and the country was empty. At that time, he was unable to fight back, so he stopped fighting and tried to recover his strength. However, the state of Yue enriched itself with its captured wealth and strengthened its confidence in defeating the State of Wu. At this time, the goal of the king of Yue went further, that is, to gain the status of the leader of the Central Plains, and "revenge" was just an excuse.
In 478 BC, Wu suffered an unprecedented famine. Gou Jian thought that the time was ripe for a massive attack on Wu. After full preparation, he led the army to March, defeated Wu Jun in Li Ze (water name, now Suzhou South), and Fu Cha died. Some even destroyed Wu, crossed the Huaihe River and formed an alliance with the vassal States, and finally realized the last dream of overlord in the Spring and Autumn Period.