1, internal productivity declines;

2. The external environment is unstable for a long time;

3. The concept of the ruling class in Xia Dynasty;

4. Personal factors of "Jie" in summer (indulging in debauchery all day, building great projects and getting close to the people. )

Reasons for the demise of Shang:

1. In the late Shang Dynasty, most slave owners and nobles lived a luxurious and decadent life and treated slaves very cruelly. Such as human sacrifice, human sacrifice;

2. The exploitation and enslavement of civilians and slaves by slave owners and nobles are increasing day by day, and class contradictions are intensifying day by day;

3. The rulers of Shang Dynasty waged wars with foreign countries year after year, and fought against Japan on a large scale. Almost all the young and middle-aged people in China have been recruited, which has aggravated domestic contradictions.

There were too many slaves captured in the war, and he didn't deal with the resettlement of slaves, which led to a large number of slaves rebelling.

The reason why Zhou perished:

1, earthquake, drought and other natural disasters have caused great losses to people's lives and property, and also made the crisis in the Western Zhou Dynasty worse.

2. Zhou Liwang's extortion intensifies the exploitation of working people; It spread to Zhou Youwang, which destroyed the patriarchal clan system, and the vassals lost their trust in him by "establishing concubines after the abolition, and establishing Shu Ren after the abolition" and "playing vassals with fire".

3. With the decline of the royal family, the relationship between the vassal States and the royal power of the Zhou Dynasty gradually alienated;

4. Ethnic dogs attacked Haojing, and the Western Zhou Dynasty perished.

5. The enfeoffment system made Zhou's power empty, and even became a puppet after moving eastward;

6. The patriarchal clan system of Zhou Dynasty was destroyed, and the influence of local governors was increasing day by day; And under the banner of the royal family, "support the emperor and make the princes" and constantly develop their own power.

Qin-cruel rule, too much power.

Judging from the unification of the six countries by Qin Shihuang, the rule of the Qin Dynasty was quite brutal. Influenced by Shang Yang's political reform, the unified Qin Dynasty was still harsh. A little carelessness tortured the nine clansmen, and the construction of Epang Palace was a waste of people and money, which made the people at that time inevitably rebellious under the heavy corvee and eventually died in repeated struggles.

Another important reason is that the Prime Minister has too much power. Although it is a three-public, nine-public system, power is still concentrated on the prime minister. People say that Zhao Gao, a traitor, destroyed the State of Qin. After he became prime minister, he became more powerful and killed the minister, which led to the betrayal of relatives and friends and the gradual demise of the Qin Dynasty.

Han county parallel, reuse consorts.

After the reunification of the Han Dynasty, the Han Dynasty also followed the example of the Qin Dynasty to implement the county system, but later, in order to highlight the dignity and consolidate the rule, the county-state parallel system was implemented. In essence, the county system was combined with the enfeoffment system, and the princes were enfeoffed and the consorts were reused.

However, instead of consolidating centralization, the Seven-State Rebellion broke out, and the local governors had too much power, which seriously affected centralization. In the contest with the princes, due to years of fighting, the national strength was exhausted, which led to the demise of the Han Dynasty.

Tang dynasty-numerous buffer towns, endangering the central government.

The main reason for the demise of the Tang Dynasty lies in the vassal areas. After the reunification of the Tang Dynasty, governors were established all over the country, and officials were appointed as our envoys to govern all regions, which eventually led to the serious expansion of local power and the Anshi rebellion. Since then, the Tang Dynasty has been in turmoil again and again (such as Huang Chao Uprising and Wang Xianzhi Uprising) and finally perished.

Yuan-ethnic discrimination, ruling darkness

As early as before the establishment of the Yuan Dynasty, during the Genghis Khan period, Genghis Khan led Mongolian fighters to slaughter the Central Plains, and every time he conquered a city, he slaughtered Han people. After Genghis Khan, the rulers were more unequal to the Han people, who were far less than an animal and regarded them as slaves.

It was not until Kublai Khan's period that the Yuan Dynasty was established and Kublai Khan changed the dynasty and demanded the implementation of the Han system that the situation was alleviated, but the status of the Han people remained low. After Kublai Khan, the Yuan Dynasty was ruled by darkness and the people were poor. Finally, a people's uprising broke out and overthrew the Yuan Dynasty.

Ming-financial crisis, improper employment

After the contradiction between the central and local governments in the Song Dynasty was resolved, another contradiction also emerged, that is, imperial power and relative power. After Zhu Yuanzhang established the Ming Dynasty, Hu was killed because of the Hu Dang case, and the prime minister system that existed for more than 600 years was abolished.

However, another reason for the demise of the Ming Dynasty was improper employment. First there was Yan Song, then there was Wei Zhongxian. At different times, both of them dominated the state affairs, doing evil and killing ministers indiscriminately, which disrupted the ruling order of the Ming Dynasty. However, the "Zhang Reform", which really made the Ming Dynasty rich and strong, was completely abolished after Zhang's death, which shows the improper employment of people in the middle and late Ming Dynasty.

Qing dynasty-closed door, decadent rule.

The centralization of absolutism in Qing Dynasty reached its peak. In order to improve efficiency, the Ministry of Military Affairs was established. But under such a highly centralized rule, it has not been able to get rid of the fate of being destroyed.

The demise of the Qing dynasty lies in its closed door, blind arrogance and addiction to the Chinese dream. At the same time, the strength of western countries has been growing. After the industrial revolution, the ambition of colonial aggression of western countries expanded continuously, and finally the aggression was directed at China at 1840.

In the struggle with western countries, the Qing government repeatedly lost and fought, signed treaties and ceded land for compensation. Due to the emptiness of the national treasury, the Qing government had to increase taxes on farmers, which led to the loss of popular support and eventually died in the Revolution of 1911. As the saying goes, the world that wins the hearts of the people, the political system of the rulers and the people's hearts are antagonistic, which determines the peace and turmoil of the rule.