In the spring of 588 AD, Emperor Wendi wrote to Chen, and in October, he ordered the Prince to lead more than 500,000 troops to launch an all-out attack on Chen along the Yangtze River. At that time, Chen was "no less than 100,000", and the river guards repeatedly flew books for emergency use. Chen Houzhu was dissolute and indulgent, and "played lyrics, drank wine and wrote poems" with his ministers. In the first month of the second year, Sui led and He Ruobi crossed the river respectively, and General Zhong surrendered and led Chen Dujiankang to capture his civil and military ministers alive. The demise of the Chen dynasty and the reunification of the north and the south ended the separatist situation of more than 270 years since the end of the Western Jin Dynasty. The unification of the Sui Dynasty is conducive to social stability and economic and cultural exchanges and development between the North and the South. The unification of the North and the South in Sui Dynasty is the trend of historical development, which mainly has two important historical conditions:

1. Great ethnic integration in the north. Since the Eastern Han Dynasty, the Xiongnu, Jie, Di, Qiang, Xianbei and other ethnic minorities who have moved in one after another have no differences with the Han nationality in economic life, language, customs and habits after long-term exchanges with them. The names of these ethnic groups gradually disappeared from history. The diplomatic envoys of the North-South regime have frequent exchanges, and the ethnic contradictions between the North and the South have gradually disappeared. This has created conditions for the reunification of North and South.

2. Jiangnan economic development. The economic development in the south of the Yangtze River has gradually narrowed the gap between the economic development level of the North and the South. The economy of the Northern Dynasties has developed rapidly since the Northern Wei Dynasty. There is a lot of non-governmental trade on the north-south border, and officials from both sides are also prohibited from making profits from each other. The development of the North-South economy urgently needs to strengthen economic exchanges between the two sides and end the separatist situation.

In a short period of more than 20 years, the economy of Sui Dynasty flourished. The cultivated land area increased greatly, from19 million hectares in the early Sui Dynasty to more than 55 million hectares more than 20 years later. The output of crops has increased rapidly. At the beginning of Emperor Wendi's accession to the throne, the national treasury was empty. After more than ten years, the imperial treasures can no longer accommodate the silks collected from all over the country, so it is necessary to establish new treasures. By the end of Emperor Wendi of Sui Dynasty, warehouses in Xijing and other places were full of grain, ranging from tens of millions of stones to millions of stones. Later, when the Tang Dynasty was established 20 years ago, the treasures of the Sui Dynasty had not been used up. As stated in "Debate on the Rise and Fall of Zhenguan Politicians": "Counting the world's reserves will be available in 50 or 60 years." There were so many warehouses in the Sui Dynasty that it was rare in the history of China.

Wendi advocated frugality.

Among the feudal emperors of past dynasties, Emperor Wendi of Sui paid special attention to frugality. At the beginning of his accession to the throne, he announced that "dogs and horses should be taken to play, not enshrined." Those officials who put dried ginger in cloth bags and spices in bags for sacrifice all thought it was a waste and gave them a big reprimand. In "Zi Tong Zhi Jian", he said: "He is very self-reliant, frugal and makes good use of things, so the disadvantages should be supplemented as appropriate; Since you don't enjoy the feast, you can't eat another piece of meat; The harem was dressed in mourning. "

The opening of the grand canal

The Grand Canal in Sui Dynasty was opened from 605 to 6 10, and it was divided into four sections, as shown on the next page.

1. Tongji Canal. In 605, Yang Dizheng opened the economic canal with "more than one million people in two counties in northern Henan". As early as the early Warring States period, Wei dug a gap (the water was diverted with the Bianshui River, and turned south with the sand). Tongji canal is dredged on the basis of gap and downstream Bianhe River. From the west of Luoyang, Gushui and Luoshui were introduced into the Yellow River, and then introduced into the Bianhe River from Banzhu (short for Zhukou, the northeast side city of the Yellow River in Xishui Town, Xingyang City, Henan Province), and now it enters the Huaihe River in the southeast of Kaifeng, Henan Province.

2. if. In 605, Yang Dizheng recruited "more than 100,000 Huainan citizens" to open Hangou. As early as the Spring and Autumn Period, Fu Cha, the king of Wu, ordered the canal between the Yangtze River and Huaihe River to be dug. Because this river passes through Hancheng (now Yangzhou, Jiangsu) of the State of Wu, it is called Hangou. Han Gou of the Grand Canal in Sui Dynasty was dredged on the basis of Han Gou of the State of Wu in the Spring and Autumn Period. It goes from Yang Shan (now Huai 'an, Jiangsu) to Jiangdu and enters the Yangtze River.

3. Yongji Canal. In 608 AD, Yang Di collected more than one million able-bodied men in Hebei counties and opened the Yongji Canal. There are not enough men, but also women. Yongji Canal flows into Qinghe River (Weihe River) from the north bank of Luoyang Yellow River to the east of Qinshui River, and reaches Zhuo Jun County near Tianjin today via Shui Gu River (Baihe River) and Sanggan River (Yongding River).

4. Jiangnan water town. In 6 10, Kaijiang south river. From Jingkou to Yuhang, it is "more than 800 miles, more than 10 feet wide".

There are imperial roads, willows, more than 40 detached palaces (from Chang 'an to Jiangdu) and many granaries on both sides of the canal. On the map of the textbook "The Grand Canal of Sui Dynasty", there is also a canal that flows into the Yellow River from Chang 'an East to Tongguan, called Guangtong Canal, which was dug by Emperor Wen in 584. Located in the south of the Weihe River, it was dug to solve the problems of the Weihe River, such as sand, different depths and inconvenient navigation, with a total length of more than 300 miles. After the completion of the Sui Grand Canal, materials from north and south can reach Chang 'an directly.

The turbulent Song and Yuan Dynasties

After the demise of the Song Dynasty, the Southern Song regime established its rule in the south. In the Southern Song Dynasty, the military and civilians of loyal opposition Jin Army attacked, and the Song and Jin finally reached a peace agreement, which formed the coexistence of the Southern Song Dynasty, Jin and Xixia. During the Southern Song Dynasty, the southern economy continued to develop, and overseas trade was further expanded, basically completing the process of the shift of the ancient economic center of gravity to the south. After the war, the economy of the northern Jin dynasty has also been restored and developed, and the trend of national integration continues to develop.

At the beginning of the Yuan Dynasty13rd century, the Mongolian region was unified and the Mongolian regime was established. Since then, the Mongolian regime has conquered the regimes of Xixia, Jin, Dali and Southern Song by force, and unified China in 1279. During this period, Kublai Khan established the Yuan Dynasty in 127 1, with its capital as the capital. In order to consolidate the rule, the Yuan Dynasty established a provincial system and developed a centralized administrative system. During the Yuan Dynasty, cotton textile industry, domestic transportation and foreign trade were developed. The Yuan Dynasty maintained the rule of Mongolian nobles and carried out the policy of ethnic differentiation, which made the class contradictions and ethnic contradictions sharp during the Yuan Dynasty's rule. The peasant war at the end of Yuan Dynasty overthrew the rule of Yuan Dynasty.

Strengthening centralization in Ming and Qing Dynasties

Since the establishment of autocratic centralization, it has been constantly developing and changing in the contradictions among the landlord class, the peasant class and the landlord class. On the one hand, in order to strengthen the exploitation and oppression of the peasant class, the landlord class should constantly strengthen the state apparatus and change the way of governance. The purpose of strengthening centralization in past dynasties lies in this first place. On the other hand, the contradictions within the landlord class also prompted it to strengthen the state machine.

From a national perspective, it is a contradiction between the central and local governments. All previous dynasties strengthened the central power and weakened the local power. Reflected in: (1) Financially, "profit" belongs to the central government. Namely, financial resources are monopolized by the central government. In order to control the financial power of the whole country, the feudal dynasty took various measures. On the one hand, farmers are fixed on the land to ensure the source of agricultural tax. For example, the household registration system in the Western Han Dynasty: the Eastern Han Dynasty and some dynasties verified the national land, and the Sui and Tang Dynasties set up a household registration department in the central government to manage financial affairs. On the other hand, strengthen the management of important assets such as salt, iron, copper and coins. Such as the salt and iron monopoly in the period of Emperor Wu of the Han Dynasty. (2) Deprived of local affairs, officials are out of the emperor. (3) Judicially, laws are promulgated by the emperor and are in the hands of the state. (4) Militarily, the central government deployed the national army macroscopically, and the emperor monopolized the military power. (5) In the ideological field, cultural absolutism is promoted.

From the central point of view, it is the contradiction between the emperor and the ministers, which strengthens the power of the emperor and weakens the power of the prime minister. The system of three fairs in Qin and Han Dynasties was headed by the prime minister, and hundreds of officials were subordinate to the emperor to assist him in handling government affairs. Emperor Wu of the Western Han Dynasty established China, and Liu of the Eastern Han Dynasty "established three fairs and returned things to Taige"; The system of three provinces in Sui and Tang Dynasties divided the relative power into three parts, which reflected the strengthening of imperial power. Ming Taizu abolished Zhongshu Province, but the Prime Minister did not establish it. During Yongle period, the cabinet was established, and the Ministry of War was established in Qing Dynasty, which reflected that the imperial power had reached its peak. From the changes of the prime minister system, we can see that the emperor concentrated all kinds of power in his own hands step by step by dividing and weakening the relative power, thus effectively implementing the absolute monarchy.

The centralization of absolutism is essentially a tool used by the landlord class to rule the working people. But objectively, it has also played a certain role in safeguarding the reunification of the motherland and promoting economic and cultural development.

During the Yuan, Ming and Qing Dynasties, with the development of commodity economy, the feudal system gradually declined. The early democratic enlightenment thought is also growing. Li Zhi, a thinker in the late Ming Dynasty, accused the Confucian classics of not being "eternal supremacy" and denied that Confucius was a "born saint". He exposed the hypocrisy of Taoism. He opposes discrimination against women and oppression of businessmen. Li Zhi was a pioneer of anti-feudalism in China. In a certain sense, his thought reflects the requirements of the embryonic era of capitalism and is democratic. Huang Zongxi was a fierce critic of feudal monarchy at the end of Ming Dynasty and the beginning of Qing Dynasty. He believed that the monarchy was a "great disaster in the world", advocated "rule of law" against "rule of man", opposed emphasizing agriculture and restraining commerce, and put forward the idea of "commerce as the foundation". It was the Revolution of 1911 that finally overthrew feudal absolutism.