Chapter 3 Chapter 2 "The Capital of Emperors in Central Qin since Ancient Times"——The Capital of the Unified Dynasty

In 221 BC, Qin Shihuang, a generation of emperors, ended the long-term separatism of feudal princes since the Warring States Period, and established a vast unified country with Xianyang as its capital. Since then, Chinese history has turned a new page.After the fall of the Qin Dynasty, the dynasties continued to change, and the periods of unification and division appeared alternately. Moreover, the regimes established by non-Han ethnic groups in the surrounding areas stood side by side with the Central Plains dynasties from time to time.Although the number of capitals at this time was not as large as that of the Spring and Autumn and Warring States Periods, it was still considerable, accumulating no less than a hundred successively.Among the many ancient capitals, only today's Xi'an, Luoyang, Kaifeng, Beijing and Nanjing served as the capital of the unified dynasty.They are the five most worthy of our attention among the stars of ancient capitals. Whether it is their role in Chinese history or their status in the history of the development of ancient capitals, other ancient capitals can only hold a candle to them.

Novelists often talk about the general trend of the world with "the long-term division must be united, and the long-term union must be divided".In fact, in the long period of 2132 years since Qin Shihuang unified the six countries in 221 BC to the 1911 Revolution that sent the last feudal dynasty—the Qing Dynasty to the grave for 2,132 years, China was under the rule of a unified dynasty for 1,622 years. Down.The capital of the unified dynasty is the epitome of the country's highly developed material civilization and spiritual civilization, and it reflects the political, economic and cultural features at that time.On the other hand, the rapid development of economy and culture has also put forward new requirements for the construction of the capital.In addition, only in the period of the unified dynasty can manpower, material resources, and financial resources nationwide be mobilized to build the capital.Therefore, as the capitals of the unified dynasty, Chang'an City in the Sui and Tang Dynasties, Kaifeng City in the Northern Song Dynasty, Luoyang, Beijing and Nanjing are all cities with a large population and relatively prosperous economy and culture.

Among the unified dynasties, except for the four dynasties of Qin, Western Jin, Sui, and Yuan, which only have a history of several decades, the six dynasties of the Western Han, Eastern Han, Tang, Northern Song, Ming, and Qing all had a long history and were maintained separately. One or two hundred years or even nearly 300 years.The capital of the same unified dynasty generally seldom moves.Moreover, due to historical inheritance, after the death of the old dynasty, the new dynasty sometimes established its capital at the original site.Therefore, the five ancient capitals of Xi'an, Luoyang, Kaifeng, Beijing, and Nanjing all served as capitals for a very long time.Both Xi'an and Beijing served as the capitals of the unified dynasty for more than 500 years. If the capitals of the divided period are included, it will take more than 200 years.It can be said that since ancient times, there has been no eternal dynasty, but there have been ancient capitals that have remained unchanged for a long time.

Among the five ancient capitals, Xi'an was established the earliest.The ancient capital of Xi’an mentioned here includes today’s Xi’an City in Shaanxi Province (it was called Chang’an before the Ming Dynasty), Xianyang City and the suburbs of these two cities.As early as the early years of the Western Zhou Dynasty in the 11th century BC, the Zhou people established their country here, and Feng and Hao, the capitals of the Western Zhou Dynasty, were located in the western suburbs of today's Xi'an.Later, it was the capital of the five unified dynasties of Qin, Western Han, Xinmang, Sui, and Tang. During this period, the former Zhao, former Qin, later Qin, Western Wei, and Northern Zhou also established their capitals here. The Eastern Han Dynasty and the Western Jin Dynasty both moved their capitals. here.After the unification of the Qin Dynasty, Xi'an served as the capital of the unified dynasty for 542 years and the capital of the separate regime for more than 200 years, accounting for more than 1/3 of the time in the feudal era.Therefore, Du Fu said in a poem: "Qin has been the capital of emperors since ancient times."

The geographical environment of Xi'an as the capital is very superior.It is located on the Guanzhong Plain known as "Eight Hundred Li Qinchuan".The Guanzhong Plain is surrounded by mountains and rivers, with the Qinling Mountains in the south, the Longshan Mountains in the west, the Loess Plateau in the north, and the Yellow River in the east. It is like a huge natural castle, easy to defend but difficult to attack.At the same time, there are many passes connected with the outside world, especially in the east, there is an east-west channel between Xiaoshan and Hanshan, connecting Guanzhong and Guandong (the two are now the Yellow River between Shaanxi and Shanxi, and Hangu in Lingbao City, Henan). Guan and Tongguan in Shaanxi) and even the Central Plains are connected to facilitate its eastward development.Before the middle of the Tang Dynasty, my country's economic and cultural center of gravity was in the middle and lower reaches of the Yellow River, and Guanzhong was undoubtedly the most ideal place to control this area.Xi'an is located in the middle of the plain and slightly east. The Weihe River traverses the plain from west to east, flows through the north of Xi'an City, and flows into the Yellow River at Tongjiao, which provides irrigation and shipping facilities for Xi'an.Therefore, Xi'an is a pearl conceived in the Guanzhong Plain.

The flames of war at the end of Qin Dynasty burned Xianyang to ashes.Liu Bang started in Guanzhong, but his left and right ministers were all from Guandong, and they all advised him to make Luoyang his capital.Only counselor Zhang Liang persuaded Liu Bang to accept Lou Jing's suggestion and set his capital in Guanzhong. Because Guanzhong is fertile and wild and the situation is dangerous, it can be guarded by the geographical obstacles in the south, west and north, and open the east alone to subdue the Guandong princes.The princes were stable, and they transported grain to the capital through the Yellow River and the Weihe River (the ancient government stipulated that the grain should be transported to the capital or other places); the Kanto has changed, and the Yellow River and the Weihe River are also enough to transport military grain.Zhang Liang's words moved Liu Bang and decided to make Chang'an his capital.In the first year of Emperor Hui of the Han Dynasty (194 BC), a large-scale construction was carried out on Chang'an, and Chang'an began to emit dazzling brilliance.

Chang'an City in the Western Han Dynasty is located in the northwest suburb of today's Xi'an City, with a circumference of 25 kilometers and an area of ​​35 square kilometers.Viewed from a plane, except for the east and west sides of the city, which are straight, the other three sides are concave and convex.The palaces in the city are majestic, the famous ones are Weiyang Palace, Changle Palace and Jianzhang Palace.Standing side by side on the high-lying Longshou Plain, Weiyang Palace and Changle Palace are two huge architectural complexes, where most of the life and main political activities of the emperors and empresses of the Han Dynasty took place.Jianzhang Palace was built in the period of Emperor Wu of the Han Dynasty. Its overall scale is larger than that of Changle Palace and Weiyang Palace, with a circumference of 15 kilometers. There are Feige complex roads connected.

In the Western Han Dynasty, Chang'an City had a population of about 400,000. The residential area was divided into 160 lis. The houses were row upon row, the population density was high, and there were many markets. In addition to setting up nine cities near Hengmen for trading, there were also some fixed trading markets.The streets are straight and wide, and there is a saying of "eight streets and nine streets".Most of the main streets leading to the main city gates consist of three parallel roads, going out on the left and entering on the right, and the middle one is called the imperial road, which is used exclusively by the emperor.On both sides, elms, locust trees, pines and cypresses are planted to shade the sun.During the reign of Emperor Wu of the Han Dynasty, a large lake called Kunming Pool was excavated in the southwest of Chang'an City, which was fed by nearby river water, covering an area of ​​more than 300 hectares.Generally speaking, Chang'an City was a famous city in the world at that time, and its scale was comparable to that of Rome in Europe.

The period of Emperor Wu of the Han Dynasty was the heyday of the Western Han Dynasty. The country was rich and powerful, and Chang'an was prosperous economically and culturally. "Han Shu Shi Huo Zhi" said that the treasury has tens of thousands of money, which has been accumulated for a long time, and the ropes that wear the money are rotten.The rice in Taicang is pressed year after year, and it flows out of the warehouse until it rots and cannot be eaten.All kinds of industries in Chang'an City are very prosperous, and the streets are so crowded that people can't turn around and cars can't turn around.The culture is developed. There is a special collection of national archives and books in the Weiyang Palace. The highest school in the country, Taixue, located in Chang'an, has a maximum of more than 3,000 students.After Zhang Qian's second mission to the Western Regions, Chang'an became the starting point of the Silk Road that reached as far as the eastern coast of the Mediterranean Sea.

In 25 AD, Liu Xiu established the Eastern Han Dynasty and moved the capital to Luoyang, and Chang'an began to decline.At the end of the Eastern Han Dynasty, the generals of the warlord Dong Zhuo fought in the city, causing devastating damage to Chang'an.After the Yongjia Rebellion in the Western Jin Dynasty, wars continued in the Guanzhong area, and the population dropped sharply. There were less than 100 households in the huge Chang'an, which was not as good as a large village at that time.Since then, although several dynasties of the former Zhao, former Qin, later Qin, Western Wei and Northern Zhou established their capitals here and built many buildings here, they have never recovered the long-term prosperity of the past.

The revival of Chang'an City will not be until the Sui and Tang Dynasties.In the second year of Kaihuang (AD 582), Emperor Wen of the Sui Dynasty established a new city, Daxing City, in the current urban area of ​​Xi'an, and moved in the following year.In the ninth year of Daye Emperor Yangdi of Sui Dynasty (613 A.D.), the outer gate was built, thus laying the foundation of Chang'an City in Tang Dynasty. Chang'an City in the Tang Dynasty followed the old system of Daxing City in the Sui Dynasty and was continuously built.It is not like the irregular bucket shape of Chang'an City in the Han Dynasty, but approximates a regular square.The city is nine kilometers wide from east to west, eight kilometers long from north to south, and has an area of ​​84 square kilometers, 2.4 times that of Chang'an City in Han Dynasty. It was one of the largest city walls in the world at that time.The whole city is divided into three parts: Miyagi, Imperial City and Outer Guocheng.In the center of the north wall is Miyagi, also known as Daxing Palace, where the emperor lived and handled government affairs.The imperial city is in the south of the palace city, and it is the centralized office of various departments of the imperial court. In addition, the ancestral temple and the Altar of Sheji are also located in the imperial city, which are arranged on the east and west sides of the south wall.Waiguo City is located in the south of the imperial city and the east and west sides of the imperial city and Miyagi, accounting for the vast majority of the city's area. The residential area "Fang" and the commercial area "City" are neatly and symmetrically arranged on both sides of the street.The palace in the city is majestic and resplendent.The streets are straight and wide, and Li Bai called it "Chang'an Avenue spans nine days".The city is full of green trees and fragrant flowers and fruits.In addition, the Qujiang Pond in the southeast corner of the city and the Royal Garden in the north of the city are both beautiful tourist areas. The Tang Dynasty was the peak period of economic and cultural development in feudal society, which was concentrated in Chang'an.Domestic and foreign merchants gathered and distributed here, and mansions and cash cabinets specially serving merchants appeared in the city.The government has set up the Leveling Bureau and the East and West City Bureaus to manage the market.Big merchants accumulated thousands of dollars in their hands, so there appeared people who specialized in selling money ropes for a living.After the mid-Tang Dynasty (about the beginning of the ninth century), "feiqian" with the same nature as the current money order also appeared in the local area.Famous writers, artists, and scientists all came here.Du Fu left more than 1,400 poems, of which more than 200 were written in Chang'an.Eight of the twenty-four histories were published here.The sculptures, stone carvings, music, and dances here have also reached unprecedented levels. Chang'an is also an international metropolis with ties to more than 300 countries and regions.The government specially set up Honglu (Lulu) Temple and Courtyard to manage foreign affairs.Envoys, scholars, monks, and businessmen from various countries gathered here one after another, and even moved here, so that Chang'an has a bit of the color of the Western Regions in terms of social economy and culture.Nestorianism, Zoroastrianism and Manichaeism from the Western Regions were also introduced to Chang'an from Persia at this time. In the fourteenth year of Tianbao (755 A.D.), An Lushan and Shi Siming, the generals guarding the northern frontier, launched the Anshi Rebellion. Guanzhong and Chang'an fell into war, and Chang'an gradually declined.At the end of Tang Dynasty, Zhu Wen, the warlord who controlled the government, forced the citizens of Chang'an to move eastward to Luoyang collectively, and Chang'an became a pile of rubble.During the Five Dynasties, the urban area of ​​Chang'an was very small. It was expanded in the Ming Dynasty and renamed Xi'an.The old city of Xi'an today was built at that time. Luoyang is located in the Yiluo Basin in the west of Henan Province. It is adjacent to Yique in the south, Mang Mountain in the north, and Hulao and Hangu Pass in the east. It is a place with beautiful mountains and rivers, rich products, and easy to defend.However, before the Sui and Tang Dynasties, the most attractive thing for the emperors of all dynasties was its geographic location in the middle of the world, which was easier to control the east than Xi'an, and was easier to transport by water.After the unification of the Qin Dynasty, the two unified dynasties of the Eastern Han Dynasty and the Western Jin Dynasty, as well as Emperor Yang of the Sui Dynasty and Wu Zetian all settled here for a total of 249 years.In addition, the Cao Wei, Northern Wei, Later Liang, Later Tang, Later Jin and other separatist dynasties also established their capitals here for more than a hundred years.If you go back from before the Eastern Han Dynasty, as early as the Western Zhou Dynasty, Luoyang was the accompanying capital.In 770 BC, King Ping of Zhou moved his capital here from Haojing.However, at the end of the Eastern Zhou Dynasty, the royal family declined and the princes competed for hegemony, making the king of Zhou a nominal son of heaven. After Liu Xiu, Emperor Guangwu of the Eastern Han Dynasty came to the throne, he officially moved the capital to Luoyang, and built a new capital on part of the former site of Chengzhou in the Eastern Zhou Dynasty.The circumference of the city is about 14 kilometers, the area is 9.5 square kilometers, and there are 12 gates.Palaces and towers are widely distributed in the city. The main buildings, the South Palace and the North Palace, form a north-south column, with carved beams and painted buildings, resplendent and magnificent.Deyang Hall, the main hall of the North Palace, is said to be able to accommodate ten thousand people. The steps are two feet high. In front of the hall, there are five towers of red birds, soaring into the clouds that they can be seen from 40 miles away.Due to the small size of Luoyang City, many people live outside the city. Luoyang is the largest industrial and commercial city in the country, and its business flourished for a while.Carriage merchants spread all over the place; rare goods and treasures were accumulated in the capital; grain, cattle and horses trade was the most prosperous; in addition, there were bookstores.During the Eastern Han Dynasty, the starting point of the Silk Road moved eastward to Luoyang, and many foreign businessmen came to Luoyang. The academic culture in Luoyang is also flourishing unprecedentedly.The government has libraries and research institutions such as Dongguan, Pinglian, Lantai and Shishi. Baihuguan was the main forum for debates on Confucian classics at that time.There were more than 30,000 Taixue students at most.Many literati lived here for life.Many immortal works, such as Ban Gu's "Hanshu" (my country's first dating history book), Xu Shen's "Shuowen Jiezi" (my country's first calligraphy book), have come out here.The famous scientist Zhang Heng created the Armillary Sphere and Houfeng Seismograph here.Lingtai, the earliest astronomical observatory in my country, was also established here. At the end of the Eastern Han Dynasty, the warlord Dong Zhuo burned all his palaces in Luoyang, and Luoyang was completely destroyed.During the Wei Dynasty of the Three Kingdoms, palaces such as Zhaoyang Hall, Taiji Hall and Zongzhangguan were built in Luoyang, and a pond was excavated in Fanglin Garden to meet the needs of the ruler's life.But as far as the entire Luoyang City is concerned, it is still sparsely populated.During the Western Jin Dynasty, Luoyang had a large population, and its industry and commerce showed a scene of prosperity.There are three major markets of gold, horse and sheep in the whole city, and the opening and closing of the market are announced by drumming at the specified time every day.The nobles live extravagantly, and there are many gorgeous buildings.But the Western Jin Dynasty lasted only forty or fifty years, and Luoyang was reduced to a pile of rubble and ashes in the last years of the Western Jin Dynasty. After the Northern Wei Dynasty unified the north, the capital was moved from Pingcheng (now Datong City, Shanxi) to Luoyang in the 19th year of Taihe (AD 495), and the city was rebuilt on the basis of the old city of Luoyang in the Han and Wei Dynasties.Compared with the Wei and Jin Dynasties, the palace garden buildings inside and outside the city have developed, especially Buddhist buildings.The rulers of the Northern Wei Dynasty advocated Buddhism and built Buddhist temples in Luoyang. There were 1367 Buddhist temples at most, and the buildings were majestic and beautifully structured.The famous Longmen Grottoes (in the south of today's Luoyang City) were built during the Northern Wei Dynasty.Residential areas are called "li", and there are 220 li in the whole city.Among them, the residents in Tongshang, Dahuo, Tuning, Lelu, Yanji (Guestimate), Zhishang (Shangju), Cixiao, Fengzhong, etc. make a living by doing business, playing music, brewing wine, and selling coffins. Guizheng, Guide, Muhua, Muyi and other villages are used to resettle frontier immigrants who moved inward.After the fall of the Northern Wei Dynasty, Luoyang became ruins again due to war damage. During the Sui and Tang Dynasties, Luoyang started its most glorious and magnificent page.After Emperor Yang of the Sui Dynasty ascended the throne in 604 AD, he changed Luoyang to Tokyo, rebuilt a new city 18 miles west of the old city of the Han and Wei Dynasties, and moved tens of thousands of wealthy businessmen across the country to Luoyang.The new city straddles both sides of the Luoshui River, with a circumference of about 55 miles. It is an irregular rectangle with a width in the south and a narrowness in the north.Both the Miyagi and the Imperial City are located in the higher terrain in the northwest corner of the city, with the Miyagi in the north and the Imperial City in the south.The central halls of the palace city and the central gate of the imperial city all face Yique Mountain. The whole city takes this as the central axis, which is not only majestic, but also condescending and convenient for defense.In the west of the city, there is Xiyuan, with a circumference of 200 li. Exotic flowers and plants, rare birds and animals are widely distributed in the garden, and 16 palaces and courtyards have been built along Longlin Canal for the emperor to visit.In the Sui Dynasty, there were 120 residential areas and three "cities" in Fengdu, Datong and Tongyuan in the city.The three cities cover a vast area and are prosperous in business. Fengdu City, the largest, has a radius of eight miles. It is said that there are 120 industries in the city, more than 3,000 shops, and there are more than 400 shops around. While building Tokyo, Emperor Yang of the Sui Dynasty diverted Jianshui and Luoshui from Xiyuan in Luoyang to the Yellow River.Soon, the Grand Canal and Yongji Canal, which runs from north to south and intersects with the Yellow River, were built.In this way, by boat from Luoyang, you can reach Yuhang (now Hangzhou, Zhejiang) in the south and Zhuojun (southwest of Beijing today) in the north. Luoyang has become the center of land and water transportation in the country, and its economy and culture are more prosperous.During the reign of Emperor Yang of the Sui Dynasty, the capital was moved from Chang'an to Luoyang.Emperor Gaozong and Wu Zetian of the Tang Dynasty often lived in Luoyang. At that time, people called Chang'an and Luoyang the "two capitals of east and west", and their status was comparable. After the Anshi Rebellion in the middle of the Tang Dynasty, Luoyang was severely damaged, and less than 1/10 of the preserved buildings began to decline.Although the Houliang, Later Tang, and Later Jin (less than two years ago) established their capitals here during the Five Dynasties, they are still in decline.During the Northern Song Dynasty, Luoyang once recovered and became the academic and cultural center of the Northern Song Dynasty.But after the fall of the Northern Song Dynasty, Luoyang declined day by day. After the decline of Chang'an and Luoyang, Kaifeng rose to the east of Luoyang and became the capital of the unified dynasty. As early as the Warring States period, Kaifeng was a world-famous capital, and that was Daliang, the capital of Wei mentioned in the previous section.In the 22nd year of Qin Shihuang (225 BC), the Qin army flooded Daliang, which suffered a devastating blow.From then until the Sui Dynasty, Kaifeng was just a small town in a prefecture and county. After the unification of the country in the Sui Dynasty, Emperor Yang of Sui dug the Grand Canal connecting the north and the south in order to obtain rich products in the Jianghuai River Basin.Kaifeng is located at the intersection of the Grand Canal and the Yellow River. Ships coming from the south generally turn into the Yellow River near Kaifeng. Kaifeng has developed into a transportation hub extending in all directions.In the middle and late Tang Dynasty, with the deepening of the court's dependence on the southern economy, Kaifeng's status continued to rise. During the Five Dynasties, Zhu Quanzhong of the Later Liang Dynasty first established the capital in Kaifeng, and then moved the capital to Luoyang a few years later.Since then, the Later Jin, Later Han and Later Zhou successively built their capitals here.These four small imperial courts did not establish their capital here for a long time, only 33 years in total.Due to the frequent wars at that time, except for the initial construction of the outer city of Kaifeng in the later Zhou Dynasty, the development of Kaifeng was not large, and it was still about the same size as the Tang Dynasty.However, since Kaifeng was established as the capital during most of the Five Dynasties, Chang'an and Luoyang gradually declined, and Kaifeng has become the political center of the north.In 960 A.D., the Northern Song Dynasty established its capital here, and Kaifeng became the national political, economic and cultural center, entering its golden age. The Northern Song Dynasty carried out large-scale construction on Kaifeng.Since Kaifeng is located on a plain, it was the site of the Four World Wars and there was no danger of mountains and rivers. The rulers of the Northern Song Dynasty paid special attention to the construction of Kaifeng City.Kaifeng City adopts the form of a set of cities in the city, which is divided into three layers from the inside to the outside, namely the palace city, the inner city and the outer city.The circumference of Miyagi is five li, and it occupies the middle of the whole city. The main buildings are basically symmetrical and arranged very neatly.The inner city has a circumference of 20 miles and is a commercial area and a residential area.The outer city has a circumference of 48 miles and is also a residential area and a commercial area.The outer city is the first line of defense for military defense, so the city wall is solid and majestic, and there are horse faces, battle sheds and other defense facilities every 100 steps on the city.The moat outside the city is 50 steps wide and 1 Zhang 5 feet deep. The river gates passing through the urban area are specially equipped with iron windows and doors to strengthen defense.City streets and city gates match.The main trunk line is called Yulu, and there are 4 lines in total, from which many branches are separated, criss-crossing into a chessboard shape, leading to various city gates, forming a city transportation network extending in all directions.Residential districts are divided into two levels, Xiang and Fang, which are divided into eight chambers, with 120 squares under its jurisdiction.Every 300 steps in the streets and alleys, a military patrol station is set up, with five or six soldiers, responsible for night patrol, fire prevention and security. Kaifeng is a water and land city with convenient transportation.Four rivers, including Jinshui River, Wuzhang River (Guangji Canal), Cai River, and Bian River (the name for the Grand Canal in Song Dynasty), pass through the city, leading to Jiangnan, Shandong and central Henan respectively. Continuously concentrated in the city of Kaifeng.In particular, the Bianhe River is even more important. At that time, people said that the Bianhe River "led the rivers and lakes, benefited the South China Sea, half of the world's wealth, and the department stores of the mountains and rivers, all came from this road" ("Song History · Hequ Zhi" ).That is to say, materials not only in the south of the Yangtze River, but also as far as the South China Sea were transported to Kaifeng by this waterway, covering about half of the territory of the Song Dynasty.Because it is located in North China, it is the land center of south and north, and the land transportation is also very convenient. Kaifeng has a large population, more than one million.Business is extremely prosperous. There are more than 20,000 households engaged in business. There are more than 6,400 shops registered with the government alone. There are many people with assets of more than 100,000 yuan, and the maximum can reach one million.In addition, there are many centralized trade markets.The catering service industry is particularly developed, and various restaurants, restaurants, and tea houses line up in rows.The immortal picture scroll "Surfing the River During the Qingming Festival" painted by Zhang Zeduan, an Hanlin painter during Emperor Huizong of Song Dynasty, is a vivid portrayal of the prosperous scene in Kaifeng's market at that time.Kaifeng's handicraft industry is also extremely prosperous, with many categories. Armor, porcelain, brocade, printing, wine making and embroidery have always been famous and occupy an important position in the country.The number of workers is also less than that of the capitals of previous dynasties. There are more than 80,000 craftsmen in the official handicraft workshops alone. Kaifeng culture is very developed.In addition to Taixue, there are also various specialized schools such as law, martial arts, arithmetic, calligraphy, painting, and medicine.The Chongwen Academy of the National Library and other collections of hundreds of thousands of volumes of books from all over the country not only serve the rulers, but also provide convenience for private writing.Famous writers such as Ouyang Xiu and Su Shi in the Song Dynasty wrote many popular proses and poems in Kaifeng.The four voluminous books of the Song Dynasty, "Taiping Guangji", "Taiping Yulan", "Cefu Yuangui", and "Wenyuan Yinghua", were all compiled by the government organization in Kaifeng at this time.The Song Dynasty was an era when science was relatively developed in the history of our country. At that time, some advanced scientific instruments and weapons, such as Su Song’s water transport instrument (an astronomical instrument that uses water to drive the wheel to run), were made of gunpowder earlier in the world. Gunpowder arrows, weapons of all kinds, were first produced in Kaifeng. Kaifeng was established as the capital in the Northern Song Dynasty, and it lasted 168 years through the Nine Emperors.In the second year of Jingkang (1127 A.D.), the Jin army captured Kaifeng and destroyed the city.Shipping on the Bianhe River was interrupted, and the river course was gradually blocked. Since then, Kaifeng has been deteriorating.Both the Jin and Ming dynasties once set Kaifeng as the accompanying capital, and even moved the capital to Kaifeng at the end of the Jin Dynasty. However, due to wars, especially the repeated flooding of the Yellow River, not only the natural environment was destroyed, but also the economic development of Kaifeng was affected. The glory of the past. After the decline of Kaifeng, Beijing followed suit and became the political center of the country.From the Yuan Dynasty to the fourth year of the Yuan Dynasty (1267 A.D.), the Yuan Dynasty moved its capital here, and Beijing began to become the capital of the Yuan, Ming and Qing dynasties (except the early Ming Dynasty). It was established as the capital for 591 years.In addition, during the period of the Sixteen Kingdoms, Yan Zeng used this place for eight years, and the Liao Dynasty used it as the accompanying capital. After the first year of Jin Zhenyuan (1153 AD), the capital was moved here, and until the second year of Zhenyou (1214), the capital was moved to Kaifeng.If we go back further, the history of Beijing as the capital can be traced back to Ji, the capital of Yan State in the 11th century BC. Beijing is located on the edge of the North China Plain, with plains in the east and south, and mountains in the west and north.If you go south along the North China Plain, you can reach the Central Plains; if you walk east along the Yanshan Mountains, you can reach the forest sea and snow fields in the northeast, where the Jurchen, Manchu and other frontier ethnic groups lived in historically; It is the homeland of frontier ethnic groups such as the Huns, Xianbei, and Mongolia.In history, due to various complicated reasons, there were frequent conflicts and wars between the regimes of the frontier ethnic groups and the dynasties of the Central Plains.Therefore, Beijing was not only a bridgehead for the frontier ethnic regimes to go south, but also an important city for the Central Plains dynasty to resist the surrounding ethnic armies.Once the border situation eased, Beijing became the center of economic and cultural exchanges among various ethnic groups.In this context, Beijing's status is rising day by day. After the unification of Qin Dynasty, Beijing has always been an important city in the north of the Central Plains Dynasty.Qin Shihuang rebuilt the Yan Great Wall in the north and sent troops to garrison it.Emperor Yang of the Sui Dynasty and Emperor Taizong of the Tang Dynasty all stationed here when they conquered Gaoju [gougou] Li.During the period of the Sixteen Kingdoms, Qianyan from the Liaohe River Basin once established its capital here for several years. During the Liao and Jin Dynasties, Beijing entered a turning point in its history.Today’s Jinhai River, Juma River in Hebei Province, and the area north of the Inner Great Wall in Shanxi Province belonged to Liao’s rule during the period of opposition between Song and Liao. It was called Yanyun Sixteen Prefectures, and Beijing was the center of Yanyun Sixteen Prefectures. Mansion, one of the accompanying capitals of the Liao Dynasty.The city has a radius of 36 li and is divided into 26 squares. The industry and commerce have a certain scale, and many famous Buddhist buildings have been built. In the Jin Dynasty, the Jurchen forces reached the north bank of the Huaihe River and the north slope of the Qinling Mountains, ruling a small half of China.For the convenience of ruling, they moved the capital from Huining Mansion in the north (now south of Acheng City, Heilongjiang) to Beijing, which was called Zhongdu.Jin carried out large-scale construction in Zhongdu City.The reconstruction and expansion of Zhongdu City refer to the regulations of Kaifeng, the capital of the Northern Song Dynasty. The city has three layers, and the outermost big city has greater expansion than the old city in the east, west, and south.The perimeter of the big city is 37 miles, and it is slightly square, with three gates on each side.In front of the central part of the city is the imperial city, and within the imperial city is the palace city.To the south of the north gate of the city is the largest market in the city, where all kinds of marine and land department stores gather, the streets are wide and tidy, and the palaces are magnificent. It is said that there are more than 220,000 residents, which is like a big city.Many places outside the city, such as Tongyuan in the west of the city and Qionghua Island in the northeast of the city, have been built into beautiful scenic spots.The famous Marco Polo Bridge across the Yongding River in the southern suburbs was also built in the Jin Dynasty. In the third year of Jin Zhenyou (1215 A.D.), the Mongolian army invaded the capital and burned it down.When Kublai Khan came here in the first year of Yuan Zhongtong (AD 1260), all he saw was a desolate scene of "filled with rubble and forests of thorns".However, Emperor Shizu of the Yuan Dynasty decided to make Beijing his capital with the great talent and strategy of unifying China. In the Yuan Dynasty, Beijing was called Dadu, also known as "Khan Bali", which means "City of Great Khan".The city is divided into three parts: Ayutthaya, Imperial City and Miyagi. The circumference of Ayutthaya is 28.6 kilometers, slightly longer from north to south, and rectangular in shape.There are three main palaces in the imperial city, Improvised Holy Palace, Longfu Palace and Miyagi.Xingsheng Palace is the palace of the Empress Dowager, and Longfu Palace is the palace of the Prince.Miyagi, also known as Ouchi, is the place where the emperor lived and is the predecessor of today's Forbidden City.On the plan of Ayutthaya, there is an obvious north-south central axis that runs through the center of the entire palace city.The capital of the Yuan Dynasty was neatly planned and orderly, with magnificent palaces, beautiful and profound palaces and towers, and magnificent splendor, which is incomparable in the Liao and Jin Dynasties.In order to meet the demand for materials in the south, the Yuan Dynasty also excavated a canal from the north of Hangzhou, through today's Shandong and Hebei, to the city of Zhongdu (the predecessor of today's Beijing-Hangzhou Grand Canal). In the early Ming Dynasty, it was called Beiping.A few years after Zhu Yuanzhang's death, Zhu Di, the vassal king who was originally entrusted in Beiping, led his troops south to overthrow Zhu Yuanzhang's successor, Emperor Jianwen, proclaimed himself emperor (that is, Ming Chengzu), and began to prepare to move the capital to Beiping.In the first year of Yongle (AD 1403), it was renamed Beijing Shuntianfu, and the capital was officially moved to Beijing in the 19th year.It took 15 years in the Ming Dynasty to carry out major renovations to the metropolis of the Yuan Dynasty.Slightly south of the former site of Yuan Da Nei, the Forbidden City and the Imperial City were rebuilt on a large scale, and a moat was dug around it.In addition, the large-scale Temple of Heaven, the Temple of Mountains and Rivers (later renamed the Temple of Xiannong), and the Temple of Sun, Temple of Moon and Temple of Earth distributed in the eastern, western and northern suburbs were also built, basically laying the foundation for the old city of Beijing.The Qing Dynasty completely followed the Beijing city of the Ming Dynasty without any major changes. However, the Qing Dynasty spent a lot of manpower and material resources to build an unprecedented scale and magnificent Summer Palace, Yuanmingyuan and other isolated palace complexes in the western suburbs of Beijing. During the Yuan, Ming and Qing dynasties, Beijing's economy and culture were very prosperous.Italian traveler Marco Polo introduced the situation of Yuandadu in vivid language in "Marco Polo's Travel Notes". He said, "You must know that there is a large and prosperous ancient city called Khan Bali". The commerce is developed and the goods are abundant. "Foreign foreign objects imported into this city with huge prices are incomparable to all cities in the world."During the Ming and Qing Dynasties, Beijing was the most prosperous city in the country.There are many shops, and goods from all over the world are available.In the Qing Dynasty, Xuanwu, Zhengyang, and Chongwen were the most prosperous. Rich merchants and merchants mostly operated industries and commerce here. Beijing was also a famous cultural capital well-known at home and abroad at that time.In the Ming Dynasty, Beijing Guozijian had more than 10,000 students at its peak.The largest collection of books in my country, "Yongle Dadian", and the largest series of books, "Siku Quanshu", were compiled here.Beijing is the cradle where the well-known ancient drama form Yuan Zaju grew up, and Peking Opera, a treasure of national culture, was also born here.The famous scientist Guo Shoujing conducted scientific research here, the outstanding dramatist Guan Hanqing, and the great writer Cao Xueqin all wrote their masterpieces here. From Zhu Yuanzhang's capital in Nanjing in the early Ming Dynasty to the 19th year of Yongle (AD 1421) when Zhu Di officially moved his capital to Beijing, Nanjing served as the capital of the unified dynasty for 53 years.Among the five ancient capitals, Nanjing was the capital of the unified dynasty for a much shorter period of time than other ancient capitals.However, before the Ming Dynasty, Nanjing had served as the capital of the southern separatist regime for a long time. Southern my country has a vast territory, and the Chengdu Plain and the middle and lower reaches of the Yangtze River have developed earlier in history.Nanjing is located on the edge of the middle and lower reaches of the Yangtze River Plain, only 300 to 400 kilometers away from the mouth of the Yangtze River in the east, and borders the Huaihe River Basin in the north and connects with the North China Plain.Along the Yangtze River in the north and the low mountains and hills in the eastern and southern suburbs, forming a geographical situation surrounded by three sides to the urban area.At the end of the Eastern Han Dynasty, Liu Bei visited Moling (now south of Nanjing City, Jiangsu Province) and saw the majestic mountains and mountains in this area, so he persuaded Sun Quan to take it as the center of his rule.Later, Sun Quan established the capital of the Wu Kingdom here, calling it Jianye, and Nanjing began to step into the ranks of ancient capitals. At the end of the Western Jin Dynasty, the Central Plains was in turmoil, and part of the royal family moved south. Jin Yuan Emperor Sima Rui (ruirui) established the Eastern Jin Dynasty in Nanjing to fight against the regimes of the sixteen countries in the north, and rebuilt the industry into Jiankang.Later, the Song, Qi, Liang, and Chen dynasties (called the Southern Dynasties) that followed the Eastern Jin Dynasty also used Jiankang as their capital.Sun Wu, Eastern Jin and Southern Dynasties combined have six dynasties, known as the Six Dynasties in history, and established their capital here for a total of 330 years. Sun Wu built two Jianye cities. The second Jianye city has a circumference of about 20 miles. The Qingxi and Yundu (du reading) rivers are built in the south of the city, which are connected to the Qinhuai River.Pogangdu was also dug to connect Jiankang with the prosperous Taihu Lake Basin.There is a gorgeous palace city built in the city, and the layout is roughly modeled on the scale of Luoyang City in the Eastern Han Dynasty.Because the two ancient capitals of Chang'an and Luoyang in the north were severely damaged in the war, Jiankang developed in stability and became the most prosperous city in the country at that time.During the Eastern Jin Dynasty and the Southern Dynasties, except for changing the earthen city wall to brick city wall, repairing six city gates, and expanding the imperial palace, Jianye City basically kept its original appearance. During the reign of Emperor Wu of Liang (early 6th century AD), Jiankang reached its peak, with a population of 280,000 households, making it the largest city in the country and the economic center of the south of the Yangtze River.Miyagi was built in three layers, and the urban area was also expanding day by day, reaching a width of 40 miles.The culture is very developed and has produced many excellent thinkers, writers and artists.In addition, Zu Chongzhi's precise calculation of pi and the manufacture of the guide car were also completed in Jiankang City.There are many Buddhist buildings, known as "the four hundred and eighty temples in the Southern Dynasties, how many buildings are in the mist and rain". After the Eastern Wei general Hou Jing and the Sui army successively attacked Jiankang and destroyed it wantonly, thus completely destroying Jiankang City, leaving only a small stone city as the Jiangzhou government.In addition, the business travel between the two sides of the Yangtze River all took the Yangzhou-Jingkou (now Zhenjiang City, Jiangsu) line, and Nanjing was in a long-term depression and its status declined.During the Five Dynasties and Ten Kingdoms period, the Southern Tang Kingdom (now Jiangsu, Jiangxi and Anhui) established its capital here and carried out a certain scale of construction, and Nanjing was redeveloped. It was only 50 years since Nanjing was established as the capital in the early Ming Dynasty, but it was the golden period of Nanjing's development.Zhu Yuanzhang used the manpower and material resources of the people in the south of the Yangtze River to build the Nanjing City Wall in 21 years.The city walls are all built with bricks and stones, and a mixture of glutinous rice juice, lime, and tung oil is poured into the cracks to strengthen the adhesion, so it is extremely strong.The city wall is 67 miles long, not only the first in the country, but also surpasses the city of Paris, and is the longest in the world.For defense purposes, natural soil slopes were used outside Nanjing to form an outer city with a circumference of 120 miles, including Mufu Mountain, Zhongshan Mountain, Yuhuatai and other important peaks.The imperial city is made in a square shape, with Miyagi inside.A central axis runs through the city from south to north, and all the palaces and government offices are combined along this line.And a bell tower and a drum tower are set up at a place 40 meters high in the center of the city, and they are beaten on time to tell the time. After Ming Chengzu moved the capital to Beijing, Nanjing's political status declined, but its economy and culture were still very prosperous.People at that time said: "The wealth of the world comes from the southeast, and Jinling sinks it." There are only a handful of handicraft industries such as textiles, printing, and shipbuilding in the country.The commerce is prosperous, and there are more than 10 large markets inside and outside the city.The Qinhuai River is crowded with merchant ships, and the lights at night are like a river of stars.The Guozijian on Chengxian Street in Nanjing generally has thousands of students. It is one of the highest institutions in the country. Students from Japan, Korea (North Korea), Siam (Thailand) and other countries also study here.Until the Qing Dynasty, Nanjing was still an important town in the south of the Yangtze River. After the Taiping Heavenly Kingdom Uprising in 1851, it also took this as the capital and stuck to Nanjing for 11 years.