Since the end of the Eastern Han Dynasty, Hefei has been an important administrative center and military center in the Jianghuai area, and it is a battleground for military strategists. Known as "the lips and teeth of Jiangnan, the throat of Huaihe River", "the head of Jiangnan, the throat of Central Plains".

The place name of "Hefei" comes from the record of "Summer water surges and fertilizer is applied" in Li Daoyuan's Notes on Water Classics in the Northern Wei Dynasty. Referred to as Lu, it was called Luzhou and Luyang in ancient times. After liberation, it was designated as the capital of Anhui Province. Located in the east of China, the lower reaches of the Yangtze River, the shore of Chaohu Lake and the offshore of the river. The total resident population is 7-8 million, and the urbanization rate is over 70%.

It is an ancient city with a long history, with a history of more than 2,200 years since the establishment of the Qin Dynasty. It was once ruled by Yangzhou, Hezhou, Nanyu Prefecture, Luzhou, Desheng Army and Huainan West Road, and it is the administrative and military capital of Jianghuai area.

When wars broke out in ancient China, especially when the north and the south were divided, Jianghuai was an important battlefield. The title of "lapel, throat, lips and teeth" is very realistic, which means it has important strategic significance. Northerners had Xu Lutian's natural barrier before leaving the Yangtze River, and they had it with South Renye Fang, so they could attack and retreat and defend. According to Xu Lu, southerners can seize the natural barrier of the Yangtze River, guard Xu Lu's quasi-screen in the south of the Yangtze River and wait for an opportunity to advance northward, so they are arrogant!

"Romance of the Three Kingdoms" back to the sixty-seventh "Cao Cao pacify Hanzhong, Zhang Liao sublime xiaoyaojin"

During the Three Kingdoms period, Cao Wei and Sun Wu fought for Hefei for nearly 32 years in history, and there were many land and water wars, with more than 654.38+10,000 people. At that time, Sun Quan set up a military stronghold at ruxu mouth in Jiangbei (near yuxikou today) as the pivot of Dongwu North Gate. Cao Cao sent heavy troops to defend Hefei and Wancheng (now buried hill county) as the base for attacking Sun Wu southward. Therefore, Wei and Wu often fought in these places. In 2 13, Cao Cao led 400,000 troops to attack Wu Dong in ruxu, but failed. In 2 14, Sun Quan sent generals, Gan Ning attacked Anhui, Wei captured it, and tens of thousands of soldiers and civilians guarded the city. During the Wei, Jin, Southern and Northern Dynasties, Hefei was a military frontier between the North and the South. Known as "Huai right lapel throat, Jiangnan lips and teeth", it has always been a battleground for military strategists.

This is determined by Hefei's military strategic position in history.

Hefei, located in the hinterland of Jianghuai, has developed water transportation since ancient times, connecting Huaihe River system in the north and Yangtze River system in the south. During the Qin and Han Dynasties, Hefei was an important water transport transit node between the north and the south. Goods from the north came from Huaihe River, passed through Hefei, passed through Chaohu Lake and entered the Yangtze River southward. Southern goods and vice versa. It is precisely because of Hefei's position as an important transportation hub in north-south water transport that Sima Qian recorded in Historical Records Biography of Huo Zhi: "Hefei is affected by the tide of north and south, and leather, abalone and wood will also be lost." Hefei has become one of the eighteen commercial cities in China recorded in Biography of Huo Zhi. This is also the earliest official historical record of Hefei as a place name.

It is precisely because of the convenient transportation that Hefei is a developed economic center in peacetime. During the war, it became a military center, a battleground for military strategists in past dynasties, and was devastated by the war.

First, "Huai right lapel throat"

"Huai Right", west of Huaihe River. The ancient buildings are north-south, with east on the left and west on the right. "Neck and throat", collar and throat represent key places. "Huai right lapel throat" shows that Hefei is the main traffic throat in Dabie Mountain area on the west side of Huaihe River, and both land and water can penetrate into the hinterland of Dabie Mountain.

As early as the era of Wu Chu's hegemony, the Jianghuai area around Hefei was the place where Wu Chu and China suffered repeated wars and defeats. At the same time, the gains and losses in the Jianghuai area are also related to the gains and losses of Huaihe River management.

He Lv, the king of Wu, supported Wu Zixu's political reform and Sun Wu's army and martial arts militarily after he acceded to the throne. After years in Wu Dazhi. Taking the strategy of "three divisions tired of Chu" constantly harassed Chu, and Chu was tired of coping. A few years later, Chu's national strength was seriously depleted, which led to the gradual relaxation of defense in the Jianghuai area. After six years of exhausting Chu policy, Wu took advantage of the contradiction between Chu State and Cai State and Tang State to attack Chu State in the name of saving Cai. In 506 BC, He Lv, the king of Wu, personally took Sun Wu and Wu Zixu as generals, and 30,000 soldiers marched rapidly westward along the Huaihe River, passing Cai, and "the soldiers were high and the horses were fast" and went straight into the hinterland of Chu. In the Battle of White Foal, Wu Jun defeated Chu's main force by 200,000. Ten days later, Chu was captured.

Second, "Jiangnan Lips and Teeth"

"Jiangnan", the area south of the Yangtze River. "Lips and teeth", lips and teeth, are closely related and interdependent, that is, lips die and teeth are cold.

Huaihe River and Yangtze River are not only two natural rivers, but also two natural military defense lines in the north and south. The military gains and losses in the Jianghuai area between the Huaihe River and the Yangtze River are related to the attack and defense of the two defense lines. Wei, Jin, Southern and Northern Dynasties, Song and Jin Dynasties, etc. In the era of great division between the North and the South, "defending the river must defend the Huai River" is the established principle of the military strategic defense of the southern forces.

During the Three Kingdoms period, Hefei was the military bridgehead for Cao Wei's attack on Sun Wu, eyeing Jiangnan. For decades, the offensive and defensive wars between the two sides around Hefei have been incessant. The most famous one is xiaoyaojin, where Zhang Liao wins more with less, because everyone is familiar with the Romance of the Three Kingdoms. Later, for military reasons, General Man Chong of Wei Zhengdong abandoned the old city and built a new city to continue Hefei's military defense. Later, Hefei was used as a military offensive base and a military springboard, and the army went south, and Dongwu perished, and the world returned to gold.

"Hit the Yangtze River, China before liberation!" .

In the decisive battle of the Great China Liberation War, the General Front Committee of the Battle of Crossing the River was composed of Deng Xiaoping, Liu Bocheng, Chen Yi, Su Yu and Tan Zhenlin, and Deng Xiaoping served as the Secretary of the General Front Committee. 1At the beginning of April, 949, in order to direct the whole battle of crossing the river from the front, the General Front Committee moved to Yaogang Village, Feidong, Hefei, where it directed the whole battle of crossing the river until it marched into the south of the Yangtze River after victory.

At present, there is a magnificent memorial hall for the Battle of Crossing the River on the north bank of Chaohu Lake, which deserves its honor as the command center of Hefei.

In ancient times, Huaihe River and Jiangnan were battlefields, and the neck, throat, lips and teeth were of great significance, referring to strategic places, which Hefei used to call it. During the period of Chapter 67 of Romance of the Three Kingdoms, "Cao Cao pacified Hanzhong and Zhang Liao sublimated xiaoyaojin", Cao Wei and Sun Wu fought for Hefei for nearly 32 years in history, with more than 65,438+10,000 people fighting between land and water. At that time, Sun Quan set up a military stronghold in ruxu, Jiangbei (near yuxikou today), as the pivot of Dongwu North Gate. Cao Cao sent heavy troops to defend Hefei and Wancheng (now buried hill county) as the base for attacking Sun Wu southward. Therefore, Wei and Wu often fought in these places. In 2 13, Cao Cao led 400,000 troops to attack Wu Dong in ruxu, but failed. In 2 14, Sun Quan sent generals, Gan Ning attacked Anhui, Wei captured it, and tens of thousands of soldiers and civilians guarded the city. During the Wei, Jin, Southern and Northern Dynasties, Hefei was a military frontier between the North and the South. Known as "Huai right lapel throat, Jiangnan lips and teeth", it has always been a battleground for military strategists.

At the end of the Eastern Han Dynasty, heroes rose up and the world was in chaos. From then on to 589 AD, Emperor Wendi of Sui Dynasty unified the whole country, which experienced Wei, Jin, Southern and Northern Dynasties. Apart from the brief unification in the Western Jin Dynasty, China was in a state of separatist regime for more than 300 years. Hefei, located in the middle of Anhui Province, in the hinterland of Jianghuai, has always been a strategic place for the north and the south, and is known as "the right lip and throat of Huai River, the lips and teeth of Jiangnan". "From the great river north, but to Shen Cai in the west, north to Xu Shou, in order to take the Central Plains. If the Central Plains wins Hefei, Jiangnan is embarrassed, but it is embarrassing. " Wu Hanqiu's "Theory of Land Conditions" said: "We should use it to belly Chaohu Lake, control Huaihe Lake, fake it, and dive into Anhui Province." Because of this, in this land of Hefei, after the Wei, Jin, Song, Qi, Liang and Chen dynasties, there is not a day of war. Especially in the Three Kingdoms period, Hefei was the focus of repeated battles and defeats in Wu and Wei Dynasties, so Hefei became a famous ancient battlefield of the Three Kingdoms, and the sites of the Three Kingdoms were all over urban and rural areas. Up to now, sites such as xiaoyaojin, Qi Fei Bridge, Jiaonutai, Huilong Bridge, Lakeside Pond and Three Kingdoms New Town still exist.

Liu Fuzhi Hefei

In the fifth year of Jian 'an in Xian Di (AD 200), Bing Lin, the satrap of Lujiang, attacked and killed Xiang Yan, the secretariat of Yangzhou, and Gan Mei and Xu Lei gathered tens of thousands of people to fight between Jianghuai. When the imperial court was in peril and the world was in chaos, Cao Cao moved Yangzhou to Hefei in order to control the Jianghuai passage and consolidate the north-south territory of Huaihe River, and appointed Liu Fu as the secretariat of Yangzhou. Liu Fu was born in Suixi County, Anhui Province. In 20 1 year, "riding Hefei alone to build an empty city" and establishing national governance. Hefei at that time, because of the war, the population fled, the fields were deserted and the city was in ruins. In this case, Liu Fu decided to start with reclaiming farmland and restoring local agricultural production. He recruited a large number of refugees and provided them with all or part of the means of production, such as plows, cattle and other agricultural tools and seeds, so that farmers who lost their reproductive ability in the war could restore their ability to operate independently as soon as possible. In order to improve agricultural production conditions, he vigorously built water conservancy projects. In just a few years, Liu Fu has made outstanding achievements in management and cooperation, and established a military center for Cao Wei Group on the defense line of "breaking the county between Jianghuai and Jianghuai". According to "The History of the Three Kingdoms Shu Wei Liu Fuchuan", it is recorded that "the people enjoy their government because of their kindness, and tens of thousands of refugees have returned from abroad. So we gathered all the students, set up schools, widely planted thin fields, cultivated rice fields with little skin, Confucian skin, Qimen and Wutang, and the government, the people and the livestock. It is also a high fortress, woven into tens of millions of straw mats with many building blocks and stones. It is beneficial to save thousands of fish paste in order to prepare for war. " Liu Fu stayed in Hefei for nine years, which turned Hefei into a "giant town" of Wei State, and made Sun Wu's army "never go back to the river to see the Jianghuai". At the same time, Liu Fu's activities in Hefei, such as reclaiming wasteland to build water conservancy projects, improved the agricultural production conditions in Hefei, promoted the historical process of regional agricultural development in Hefei and played an important role in the economic recovery at that time.

Zhang Liao Wei town xiaoyaojin

In the 13th year of Jian 'an in the Eastern Han Dynasty (AD 208), Cao Cao basically unified the north, and his strength increased greatly, preparing to go south to destroy Liu Bei and Sun Quan. However, because Sun He was defeated in Chibi, the situation changed greatly. During the five or six years after Battle of Red Cliffs, Cao Cao has been fighting in the Jianghuai area, trying to break through the moat of the Yangtze River and unify Jiangdong from here, but he was stubbornly resisted by Sun Wu. Cao Cao had to change his strategy. In order to avoid being attacked on both sides, he temporarily abandoned the unification of Jiangdong and sent general Zhang Liao to station troops in Hefei to rest his troops. On the other hand, he led an army to the west to explore Zhang Lu, trying to seize Hanzhong and further strengthen its strength. In August of the 20th year of Jian 'an (AD 2 15), Sun Quan, the Lord of Wu, personally led 65,438+10,000 troops to attack Hefei on the occasion of Cao Cao's Western Expedition. At that time, only Zhang Liao, Li Dian, Lejin and Xue Mian were stationed in Hefei. The two armies confronted each other and were outnumbered. Before Cao Cao went to war, it was estimated that Sun Quan might invade Hefei again. Therefore, he wrote an order in advance, sealed it in a wooden letter, and gave it to Yan Xue, the guard, asking him to "be a thief" and act as planned. Sun Quan, Enemy at the Gates, Xue Mian and other generals opened the letter and saw the order: "If Sun Quan arrives, General Zhang and General Li will go out to meet him, General Le will defend him, so there is no need for the army to fight." In Cao Cao's view, Zhang Liao and Li Dian are both valiant soldiers who can fight well, so let them go out, and Lejin is a shrewd man, so let them guard the city; Civilians Xue Zan did not take part in the war. The generals looked at the orders, full of doubts. Le Jin, Li Dian, etc. It is believed that the strength of the two armies is very different, so it is difficult to win in the battle. When Zhang Liao saw this, he got up and said, "Cao Gong is going to war today. If we wait for reinforcements to come and save us, even if reinforcements arrive, we will have been defeated by Wu Jun. Now Wu Jun has a shaky foothold and takes the initiative to attack in order to defeat its spirit and hold the city. " Le Jin and others listened to Zhang Liao, but they still hesitated. Zhang Liao said angrily, "Success or failure depends on this battle. If you doubt it, I, Zhang Liao, will decide for myself. " Li Diansu is at odds with Zhang Liao. At this time, seeing that Zhang Liao was so determined, he also made a generous statement: "Since the general has made up his mind and put all his eggs in one basket, how can he sacrifice justice for profit?" So, people listened to Zhang Liao's suggestion, recruited 800 people who dared to die overnight, and held a banquet to strengthen their military strength. The next morning, Zhang Liao armed himself with a halberd, shouted "Zhang Liao is coming" and led the troops into the enemy line. At this point, Wu Jun, at a loss. Zhang Liao even killed dozens of people, and killed two generals, including Chen Wu, Soochow, forcing Sun Quan to take his life. Sun Quan was frightened and climbed up a mound in a panic, holding a halberd to guard himself. Wu Jun saw Zhang Liao and serenade, and quickly mobbed him and surrounded Zhang Liao for several layers. Zhang Liao waded, sprint, fight our way out, led his dozens of people rushed out of the tight encirclement. At this time, Li Dian also brought people to meet, and the two sides fought until noon. Wu Jun suffered heavy casualties and morale was greatly reduced. Zhang Liao saw that the purpose of the war had been achieved, so he led the people back to the city and strengthened their defense. After that, although Sun Quan continued to attack the city for more than ten days, he could not break the city and had to retreat and return. When Wu Jun retreated one after another, Sun Quan and several generals patrolled the north shore of xiaoyaojin, which happened to be discovered by Wei Jun. Zhang Liao immediately raided Sun Quan on multiple troops. Wujiang Gan Ning and Zhang Liao fought hard, and Ling Tong led Sun Quan to break through. When Sun Quan and others rode to Xiaoyaojin Bridge, they saw that the south plate of the bridge had been demolished and could not be crossed. At this critical juncture, Wu Li used his quick wits and waved a whip to "help the horse" behind Sun Quan's horse. The war horse jumped up and flew to the bridge, and Sun Quan fled. The history of this war is called "Zhang Liao Earthquake in xiaoyaojin", which is a famous war example set by Wei Jun during the Three Kingdoms period.

The Three Kingdoms New Town in Hefei was besieged by Sun Wu again and again. In the first year of Wei Qinglong (AD 233), General Man Chong of Wei Zhengdong went to Wei Mingdi, saying that "He Fei faces rivers and lakes in the south and Shouchun in the north", and Wu Jun besieged the city in the north, "according to the water"; And Wei "officers and men to save it, first Pojun, and then clear"; It is "easy" for the enemy to attack, but "difficult" for the soldiers to save. Therefore, Man Chong suggested: "Move the soldiers in the city outside the city", and "there are strange dangers to follow" 30 miles west of Hefei, and build another new city here to lure Wu Jun away from the waterway and level the ground, so as to "find a way back" and defeat the enemy. At that time, many people opposed it, thinking that automatically quitting Hefei would "liberate first and then attack" and "show the weakness of the world" Man Chong said that the initiative to "move into the city" is not weakness, but falsehood, which is in line with the "circuitous way" of military strategists. With the permission of Wei Mingdi, Man Chong and others stepped up the construction of Hefei New Town. Soon, the new city will be built. In the twenty years after the completion of the new town, Wu Jun repeatedly attacked the city, but all failed. In 233 AD, just after the new town was built, Sun Quan sent his troops into the encirclement. When Man Chong got the news, he said to the generals, "Now that Sun Quan knows that I have moved to the city, he must be arrogant among the soldiers. I came here today with great fanfare, and I am sure to win. Although I dare not act rashly, I have to go ashore to show my military capacity. " So, Man Chong sent six thousand troops to wait for him in the hiding place of Feishui. As expected, Sun Wu went ashore to show off his strength. At this time, Wei Jun's ambush suddenly came out, and Sun Wu's army was caught off guard. Wu Jun was far away from the waterway, and did not dare to attack on the shore rashly. Yao Bing retreated after being frustrated. Man Chong created a surprise attack. In the second year of Wei Qinglong (AD 234), Sun Quan led 654.38+ ten thousand troops to storm the new city again. Man Chong was afraid of being outnumbered and wanted to give up the new town and retreat to Shouchun. According to the Records of the Three Kingdoms, Shu Wei, Ming Di, Cao Rui, and Wei Mingdi resolutely refused to retreat, saying, "The first emperor decided to unite as the east, Xiangyang as the south, and Qishan as the west. If the thief comes to break under the three cities, the land will compete. " Ming Di pro-imperial dragon boat crusaded against Sun Quan. Man Chong struggled to defend the city, raised strong men, turned them into torches, set fire to Wu Bing's siege equipment, and hit Sun Quan's nephew Sun Tai with random arrows, finally forcing Sun Quan to withdraw from the encirclement. In the fifth year of Wei Jiaping (AD 253), the year after Sun Quan's death, Wu Taifu Zhuge Ke led 200,000 troops to drive straight into Huainan and besieged Hefei New Town for several months. At this time, there were only 3,000 people guarding the city in Wei Jun. General Zhang Te of Wei saw Wu Dajun's attack, fearing that the people would be in trouble, he would stick to the city and not fight with Wu Jun. Zhuge Ke commanded soldiers to build heaped-up mountains along the city base, determined to break the city. Seeing that the new city was about to fall, Zhang Te ventured to Wuying to surrender. He made a plan and said to General Wu, "I have no intention of fighting again. However, Wei Law stipulated that I could not be rescued by reinforcements after being besieged for a hundred days. Although I fell, my family was not allowed to sit together. Today, our city has been besieged for more than 90 days. Although the city will fall, half of the people are still unwilling to surrender. Please allow me to persuade again and submit the roster tomorrow. " Wu Jun was caught, so he stopped the siege. The defenders in the city got a respite, blocked the gap in the city wall overnight and stubbornly held their ground. Wu Junjiu couldn't attack for a long time and was exhausted. In midsummer, most patients were ill, but Zhuge Ke forbade his foot soldiers to get sick, disobeyed the general and went his own way, causing widespread indignation and low morale. Wei Jun reinforcements arrived, and Zhuge Ke had to lead the troops to retreat. Zhuge Ke sighed helplessly and said, "This battle is beyond my control. God won't help me." The Three Kingdoms New Town has existed for nearly 50 years. It was not until the death of Wu in the first year of Taikang in the Western Jin Dynasty (AD 280) that the new city was abolished and moved back to its original site. Xincheng site is located in the northwest of Hefei 15km, 2.5km east of Jiming Mountain, on the north bank of He Fei River. At present, there are 18 rammed earth mounds of various sizes. The widest part of the city wall is about 30 meters and the highest part is about 6 meters. The city site is rectangular, about 400 meters long from north to south and 250 meters wide from east to west, with a total area of about 654.38+ 10,000 square meters. A moat about 50 meters wide can still be distinguished around the city. Some people collected bronze three-stare blankly-shaped arrows, iron drop heads, iron anti-whiskers and other city defense weapons from the site, and the offensive and defensive strength at that time was evident.

In the Northern and Southern Dynasties, Wei Rui weir broke Hefei, which was a strategic place for repeated struggles between the northern and southern regimes. In the fourth year of Tian Jian, Liang Wudi (AD 505), Nanliang attacked the Northern Wei Dynasty on a large scale. When the Northern Wei Dynasty occupied Hefei, Wei Rui, the general of Liang School, led an army to attack Hefei. When Wei Rui arrived at the gate of Hefei, he saw that Hefei was low-lying, so he decided to build a dike to fill the city. When the dam is completed, the water will cross the boat. At this point, Wei Jiang Yang Lingyin led 50,000 reinforcements to rescue him. Seeing that the enemy was strong, Liang Jun also asked for more troops. Wei Rui said, "Enemy at the Gates, asking for help is tantamount to watching the fire from the other side. The way of a strategist is to unite as one, not to rely on soldiers. " Wei Rui took the lead and led the troops to beat back the reinforcements in Wei Zhi, so the morale was a little fixed. Since then, Liang Jun has been stationed in a small town near the weir. Wei Jun struggled to break through the small town, annihilated more than a thousand soldiers guarding the weir and pushed into the bottom of the dike. Liang Jun panicked again. Liang Jianjun, Pan Lingyou and others suggested that Wei Rui withdraw from Chaohu Lake. Wei Rui said angrily: "The general can die in the battlefield, there is no reason to retreat!" He ordered his men to insert umbrellas, fans, fans, etc. He was granted permission by the court to go to the embankment to show his determination to die. Wei Jun will never lose everything. Wei Rui built a base on the dam to strengthen its defense. The backwater is blocked and the weir is gradually full. Wei Rui launched a warship and attacked the city from all directions. Warships are taller than Hefei City. The Northern Wei army was helpless, and Du Yuanlun, the commander of the garrison, went to the city to bid, and was shot dead by Liang Jun's crossbow. All the soldiers wept at one another, feeling that the tide was gone, and they were unwilling to fight, so the marriage was broken by Liang Jun. When Liang Jun entered the city, he was "more than 10,000 prisoners", with thousands of horses and cattle and ten rooms full of silk. From then on, Nanliang moved to Yuzhou and settled in Hefei. This battle destroyed Hefei, but Liang Rui's courage was deeply appreciated by historians. Kangxi's "Hefei County Records" said: "Switzerland receives visitors day and night. Read military books at night, get up at night, and light up at dawn. It is often too late to obey its orders, so those who voted for it are back. "

Population Mobility and Economic Development During the Wei, Jin, Southern and Northern Dynasties, due to long-term separatism and frequent wars, the population of all parts of the country changed dramatically. Emperor Huan of Han lived for three years (A.D. 157), with a national population of 56.48 million, but by the end of the Three Kingdoms, after the merger of Wei, Wu and Shu, there were only over 6 million people. Therefore, Chen Qun of Wei said: "Today, after the troubled times, the people are at least a big county compared with the Hanwang era." During the Three Kingdoms period, the population decline was more serious in Hefei. Cao Wei and Sun Wu fought in Hefei for decades, which caused a large number of deaths. Sun Wu and Cao Wei often carry the population between Jianghuai to Jiangnan or Huaibei. In 20 1 year, when Liu Fu arrived in Hefei, he saw the broken scene of barren fields and scattered population. In the second year of Wu Wufeng (AD 255), Cao surrendered Wen Qin to Wu and hijacked tens of thousands of Huainan people to the south of the Yangtze River. On one occasion, Cao Cao prepared to force the people in Jiangbei to move to the mainland. As soon as the news came out, people from Jiujiang and Lujiang counties crossed the river south in succession. In a few days, from southern Hefei to downtown Anhui, it became a no-man's land. Lao Zhiyun: "During the Three Kingdoms period, the Jianghuai area was a land of war, during which hundreds of people did not live here, and there were no households in counties." In the late Three Kingdoms period, Cao Wei had obviously gained the upper hand in the war with Sun Wu, and the situation between Jianghuai tended to be stable. Sima Yi, who was in charge of Wei's state affairs, carried out a large-scale military camp operation in Huaibei area to save Wu's military capital and achieved great results. After several years of land reclamation, the army of land reclamation is everywhere in the north and south of Huaihe River. In the second year of Wei Ganlu (AD 257), there were 65,438+10,000 officers and men in Huaibei. During the period of wasteland reclamation, every time the army went out, it could always achieve sufficient food supply between the Yangtze River and Huaihe River. The reclamation of farmland by Cao Wei played a great role in restoring the social economy of Jianghuai area as soon as possible. In the first year of Xianning in the Western Jin Dynasty (AD 275), the government sent a group of public servants and handmaiden to Hefei to replace the soldiers who planted rice in the wasteland. During the Western Jin Dynasty, Hefei's economy and culture developed gradually, and there was a prosperous scene of "the land was clear and the customs were luxuriant, and all of them were better than Huaizuo". After the Eastern Jin Dynasty crossed to the south, the officials and people of the Western Jin Dynasty who stayed in the north of Huaihe River did not want to be ruled by foreign countries and moved to the south in large numbers. During the Eastern Jin Dynasty, in order to resettle them, many overseas Chinese prefectures, counties and counties were set up in the north and south of the Yangtze River for the purpose of resettling overseas Chinese, that is, organizational units named after northern place names and administrative regions were set up in the south to manage overseas Chinese from the north. In the Southern Dynasties, Song Dynasty, Qi Dynasty, Liang Dynasty and Chen Dynasty also used overseas Chinese resettlement to resettle people who moved from the north to the south. As the Preface to the History of the Song Dynasty said: "Since the Wei and Jin Dynasties, there have been more than 100 migrations, one county is four or five, and one county is two or three", "The people of Zero Dynasty and Guangxi are the people of Lu Jiu and the people of Xi" and "there will be no peace in the future". The Summary of Reading History and Geography also said: "Jin abandoned the Central Plains, and there was chaos in the north and south, and all counties and cities lived abroad." The Jianghuai area, including Hefei, is one of the areas where the Southern Dynasties placed northern expatriates. In the Eastern Jin Dynasty, Liangjun and Nanliang counties were set up in Hefei, and Chuyang in Feidong county was ruled by the county. During the Liu and Song Dynasties in the Southern Dynasties, Nanruyin County and Ruyin County were set up to govern Hefei. Shenxian County in the Spring and Autumn Period and Shenxian County in the Han Dynasty originally belonged to Yingshang County in Huaibei, and Shenxian County now belongs to Feidong County. The resettlement of overseas Chinese in the Eastern Jin Dynasty and the Southern and Northern Dynasties brought a large number of people from the Yellow River valley into Hefei, and they brought advanced agricultural production technology from the Central Plains. At the same time, aristocratic landlords used a large number of slaves and tenant farmers to reclaim land. The increase of cultivated land area and the improvement of farming technology have greatly increased the output of agricultural products. In the first year of Daxing (AD 3 18), Si Marui, Yuan Di, thought that wheat should be planted in the Jianghuai area, and called on the people to plant it underground in autumn, so as not to miss the time, and achieved good results. Therefore, the extra wheat harvested every year will be compensated even if it encounters drought or locust plague. This changed the farmers' habit of attaching importance to only one crop in the past, and promoted the development of agricultural production in Hefei.