At the end of the Tang Dynasty, the famous minister and poet Dugu was appointed as Changzhou secretariat. When he arrived, he sent a thank-you letter to Emperor Daizong, saying, "The state of Jiangdong is the best in Changzhou." The emperor gave him a doctor, a gold belt and a purple suit, and entrusted him with the kindness of Changzhou secretariat, which he will never forget. Dugu and his classmate, who was appointed as the secretariat of history, said doctor, which shows that Changzhou was in a prominent position at that time. Changzhou was promoted to Jinling County in Jin Dynasty, and/kloc-0 has been the seat of the county government for more than 600 years. Its jurisdiction varies from dynasty to dynasty. During the Yongzheng period of the Qing Dynasty, the state government often governed eight counties, and its boundary started from Jieyuan Mountain in Changshu County, Suzhou in the east and reached Lucheng in Danyang County, Zhenjiang in the west, with a width of 195 Li. It starts from Chuijiaoling, Changxing County, Huzhou Prefecture in the south and reaches the middle reaches of the Yangtze River in Taixing County, Yangzhou Prefecture in the north, with a total length of 285 miles. It connects Jingkou in the upper part, Gusu in the lower part, the Yangtze River in the north, Taihu Lake in the south, and a corner of Taihu Lake in the southeast. The river shape is better than that of Donganjia, so it is known as "Zuojiang Famous Area, supplemented by China and Wuyi". At that time, before the Changzhou government ruled, there was a memorial archway of "Wuzhong wanting to assist". (In the past, Danyang, Changzhou and Suzhou were collectively called the Three Wu, so Changzhou was the Middle Wu. During the great cause of the Sui Dynasty, after the opening of the North-South Grand Canal, Changzhou became a transportation hub of "one state, three sides, and a hundred boats and hundreds of cars". At the same time, the ruling groups of past dynasties also used canal transportation to intensify the beating and squeezing of the southern people. The wealth of Jiangnan will continuously flow into the private pockets of the rulers through this canal, as Zhang Yue said: "Half-day gifts and department stores in Yamazawa will enter from this road." As far as grain is concerned, it has become more and more important to transport grain from the south to the north since the Tang Dynasty. In the Tang Dynasty, it reached 3 million stones per year, and the highest record in the Song Dynasty reached 7 million stones. Therefore, Jiangsu, Zhejiang, Jinghu, Guangxi and Fujian roads were specially set up in the Song Dynasty to undertake these affairs. During the Hongzhi period of the Ming Dynasty, Yu Shi Tom said in his lecture, "There are two things in this house, Guantang Avenue, which leads to Jinghua in the west and Fujian and Vietnam in the east. During the period, cultural relics were presented, money and food were transported by the Ministry, officials were on business, and people prepared gifts and sent documents day and night, which was the way of the court and the way of the people's mouthpiece. " Changzhou is not only a north-south transportation hub, but also plays an important role in the military from a historical perspective. Dong Wenji, a scholar and suggestion in Qing Dynasty, wrote in Preface to Changzhou Shengxing. "The Yangtze River is a natural barrier to the north of Chang County, and Jingjiang is a horn outside the river. Jiangyin is the inside guarantee and Matosha is the reinforcement. Mengheyangshe blocks its dangers, and its potential corresponds from beginning to end, such as the snake of Changshan Mountain, which is my north gate. Taihu Lake is Tang Chi in the south of Changjun County, Yixing is the right arm, and Wuxi is the left arm. From Baidu in the west to Liangxi in the east, it is like a dragon and tiger array, taking me south. " Gu Zuyu, a famous historical geographer in Qing Dynasty, made a thorough analysis of Changzhou's military situation. He said: "Changzhou is divided into several counties, and Jinling is in its wing. In order to transfer important places and get rid of them safely, the elbow in Jingkou was sparse, and Wu Jun's throat was absolutely exhausted. If you defend Jingjiang in the north, you can protect the key of Neijiang Sea, which is enough to destroy the shield of Huainan. To the south of Yixing, it is close enough to eliminate peeping at the lake and far enough to clear the smoke of Zhejiang Rightists. In the past, it was important to defend wuyue in the southern Tang Dynasty and control Gusu in the early Ming Dynasty. " Let's take a look at the historical facts of the southern Tang Dynasty and the early Ming Dynasty: at the end of the Tang Dynasty, after the failure of the peasant uprising, the separatist forces took the opportunity to scuffle and the vast areas north and south of the Yellow River were seriously damaged. Our times make Yang Xingmi occupy Huainan Town (Haizhou in the north and Qianzhou in the south; From Changzhou in the east to Hankou in the west, the rulers of the Tang, Jin and Han dynasties in the Liang Dynasty and the Shatuo people in the north prevented the war from bringing more harm and suffering to the people in the south, and played a positive role in isolating the north and the south and ensuring that the Yangtze River basin was not invaded by northern warriors. In the east, Changzhou happens to be the junction of Nantang and Wu Yueguo. After Yang Xingmi's death, Xuwen came to power, which was called Southern Tang Dynasty. At that time, King Qian Jiao of Wu Yue sent troops to attack Changzhou. Xu Wen defeated Wu Yuebing, made peace with wuyue, avoided war, implemented a truce policy, let the people rest, and protected the environment and the people. In addition, taxes were reduced and farmers and mulberry trees were rewarded. Therefore, there is a scene of prosperity between Jianghuai. This is good for the people. At the end of the Yuan Dynasty, after Zhu Yuanzhang took Nanjing, he decided to concentrate his forces on the west and destroy Chen Youliang, who occupied Jiangzhou. At that time, according to Suzhou, Zhang Shicheng repeatedly committed crimes in Jiangyin, Changxing and Changzhou. Zhu Yuanzhang named Tanghe to defend Changzhou, and Tanghe built a city to defend it. He was in contact with Jiangyin Wuliang and Changxing Geng Bing, which became a southeast barrier. Zhu Yuanzhang praised them for "protecting one side and worrying about the East, which is a great achievement." After Chen Youliang was destroyed, Zhu Yuanzhang returned to Zhang Shicheng and marched from Changzhou, Jiangyin and Changxing, just like three sharp arrows pointing directly at Suzhou and catching Shi Cheng and San Wu Xi Ding, so Zhao Huaiyu's article "Building a City" said: "This Changzhou is fundamental." In addition, Changzhou during the Taiping Heavenly Kingdom can also illustrate this problem. In the late Taiping Heavenly Kingdom, due to the powerful joint military attack of Chinese and foreign enemies, the major towns in southern Jiangsu fell one after another, Tianjing was besieged by Zeng Guofan's Xiang army, and Su Xi was often surrounded by Li Hongzhang's Huai army and the "Chang" commanded by British robber Gordon, and fell one after another. Changzhou was sandwiched between the east and the west, and Chen Kunshu, the garrison commander of Changzhou Taiping Army, led the soldiers and civilians to stick to it. Li Hongzhang personally supervised the war,1000000 more than ten thousand Qing troops rushed out, and also assembled 3000 regular artillery teams. It took five months to win Changzhou. Chen Kunshu started a street fight with the enemy after breaking the city, and was finally arrested for exhaustion. Before he died, he said, "I want to defend Changzhou, thinking that Jinling (Nanjing) has horns ..." It is not difficult to see that Li Hongzhang is desperate to pull Changzhou out, and Chen Kunshu is willing to defend Changzhou at any cost, because Changzhou has played an echo and guarantee role in Jinling. Because of Changzhou's important position in the military, the rulers of past dynasties also attached great importance to the construction and construction of Changzhou City. According to the Ming Dynasty's "Piling King", the Changzhou City Wall began in the Jin Taikang period and was repaired and abolished several times before the Tang Dynasty, so it is difficult to test. However, according to the Records of the Three Kingdoms, since 240 AD, Wu Dong has been "managing battlements, building towers and crossing ditches" for counties and county-level cities, and has been blocked by defensive facilities. So Changzhou should have a city at that time. Judging from the existing historical data, the construction of Changzhou city wall is mainly in the late Tang Dynasty and the Five Dynasties, and in the early Ming Dynasty, it is also the aforementioned period of frequent wars. In the first year of Tang Jingfu, Yang Xingmi and Huainan made our time and sent officials to inspect the Ministry of War. Minister Tang Yan rebuilt the state with the right to build a "Inner City", with a circumference of two miles, 318 steps and a height of two feet. This is the area around the stadium today. During the Five Dynasties and Ten Kingdoms period, Changzhou was under the rule of Wang Wuyangpu. In the first year of Wu Shunyi (AD 92 1 year), Zhang Bo, the secretariat, once built the Waizicheng, with seven weeks and thirty steps. The city is 20 feet high and square, so it is called "the city of piling, just like the city of golden barrels". The southeast and northwest of the city are divided into four gates: Yingchun, Jindou, Yingqiu and Arctic. In the second year of Wu Tianzuo (AD 936), Xu Jingmai, the secretariat, built another city with a circumference of 27 Li, 37 steps and a foot high. This is the so-called "Los Angeles". There are nine gates: the east gate is called Wu Tong, which was in Hangzhou in the Southern Song Dynasty, but it was changed to Chaotianmen. The second east gate is called Huaide, the second south gate is called Guanghua, and the west gate is called Chaojingmen. In the second year of Hongwu in Ming Taizu (A.D. 1369), he was stationed in Changzhou, with wuyue in the east. Due to the large scale of Luocheng, it was difficult to hold it, so it contracted to the southeast and west and built a "new city" in Luocheng. In "Yuefu also has a life", "Cheng Wei is forty miles, the land is exhausted, the hall is built on three sides, and the southeast and the west gather." Fiona Fang, a new city, has 284 steps in ten miles, seven gates in the east, west, north and south, and the second north is the old name. The second east is changed to arrow gate, and the second south is changed to Shimen. Each gate has its own building, and there is an urn outside. The moat outside the city is 16 feet wide and 20 feet deep. It has four water gates, one is called East Watergate in the east, one is called West Watergate in the west, one is called North Watergate in the northeast and one is in the northwest. In the Yuan Dynasty, the buildings were destroyed, but the city walls were still rudimentary. In the eighteenth year of Chenghua in the Ming Dynasty (AD 1482), the magistrate Sun Ren was rebuilt, and Zhongjianmen was renamed Huaide, and Shiloumen was renamed Guanghua. After this transformation, the city wall was easily enlarged by three feet with huge stones, and it was "magnificent" and "a giant town in the southeast". Later, in the sixth year of Zheng De in Ming Dynasty (A.D.151kloc-0/), the magistrate Song Li became a peasant rebel against Liu Qi. In the thirty-fourth year of Jiajing in the Ming Dynasty (AD 1555), Jin Hao, the magistrate, defended the enemy. In the ninth year of Kangxi (AD 1670), the city wall collapsed. In the 29th year of Kangxi, Yu Kun, the magistrate, and Heng Xuan, the magistrate of Wang Yuan, were damaged by Rain City. In the fourth year of Yongzheng (A.D. 1726), the prefects of Yanghu, Wujin County and Heyou Loumen were partially repaired. In the twenty-ninth year of Qianlong (A.D. 1764), it was originally planned to be rebuilt in the twenty-fourth year of Jiaqing, but it could not be held because of the huge project. Before liberation, the city wall had collapsed and been demolished. Since liberation, all the city walls have been demolished except the section of Xishuiguan.