In a practical sense, the Qin dynasty passed the second, and the Sui dynasty also passed the second.
First of all, talk about the rise and fall of the Qin Dynasty. Qin was one of the vassal states of the Zhou Dynasty. After hundreds of years of energy accumulated outside Hangu Pass, we have the strength to get our hands on the Central Plains. If Qin Shihuang unified the six countries, he would rule the whole country 15 years. Qin Dynasty was Shang Yang's political reform and legalism. For the six eastern countries, this system is unacceptable in a short time, and it is tyrannical to the people, which leads to officials forcing the people to rebel. This system can temper blood and will in wartime, but it is absolutely unacceptable in peacetime. Moreover, the six eastern countries still have strong feelings for the native countries and have their own sense of cultural belonging.
The Sui Dynasty was founded by Emperor Wendi of Sui Dynasty on behalf of the Zhou Dynasty, but it died when it reached Yang Guang. The demise of the Sui Dynasty was mainly due to Yang Guang's haste. In fact, Yang Guang is not necessarily a tyrant. He wanted to change the contradiction between the imperial court and diplomacy in a short time. His ideal was actually achieved through the efforts of several generations. Opening the Grand Canal and building the East Capital were all completed within a few years of his succession, which was a heavy burden for the people. Three signs of Koguryo, but nothing, the people are miserable. Moreover, he wanted to weaken the influence of Guanlong Group in the imperial court and implemented the imperial examination system, which offended most of the forces of Guanlong Group. As a result, the world was in chaos, and all localities were divided into kings.
Both the Qin Dynasty and the Sui Dynasty were relatively prosperous at the beginning of their establishment, and the reason for their demise was also the people's uprising.
When the Han Dynasty and the Tang Dynasty were founded, they were very similar. Before the Han dynasty, there was a dispute at the end of Qin dynasty, and before the Tang dynasty, there was a rebellion at the end of Sui dynasty. Moreover, at the beginning of its establishment, the nomadic people in the north were very strong, and they could only save their strength and avoid their sharpness. At the beginning of the Han Dynasty, Emperor Gaozu Liu Bang was besieged by Deng Bai. In the early years of the Tang Dynasty, Turks also invaded the suburbs of Beijing. Both dynasties began to fight back against nomads after recuperation. Emperor Wu of the Han Dynasty destroyed Xiongnu and Emperor Taizong destroyed East and West Turkistan. At the end of the Western Han Dynasty, emperors mostly had nothing to do and their life span was very short. In the end, the emperor's power was sidelined, and Tang Gaozong and Li Zhi were cowardly, which led to Wang Mang's usurpation of the throne and the destruction of the Wu Zhou Dynasty and the Tang Dynasty. After the restoration of their respective countries, both dynasties experienced prosperity.
In the middle and late Eastern Han Dynasty, Liang Ji, a consort, dominated the state affairs, and the emperor's power was marginalized again. Emperor Huan of the Han Dynasty used eunuchs to remove consorts, and eunuchs controlled state affairs, and buying officials became the norm. The literati and nobles were dissatisfied with it and competed with it, which caused the disaster of party struggle. At the end of the Eastern Han Dynasty, natural disasters continued and the people were in dire straits, resulting in the Yellow Scarf Uprising. The policy pursued by the Eastern Han Dynasty to suppress the uprising was that all localities could recruit their own soldiers, and this future warlord scuffle laid a curse. After the yellow turban insurrectionary uprising was suppressed, blades' consorts led various troops to Beijing to kill eunuchs, but they were harmed by eunuchs. Dong Zhuo finally took control of the state affairs, abolished the Emperor Shao of Han Dynasty, and caused dissatisfaction in various places, and they all crusaded against Dong Zhuo. After Dong Zhuo moved to the west, various warlords scuffled, and the court was also controlled by Li Jue, Guo Si and Cao Cao. The Eastern Han Dynasty existed in name only. After Cao Pi forced Emperor Xian of Han to abdicate, the Eastern Han Dynasty completely perished.
However, after the prosperity of Kaiyuan in the Tang Dynasty, the Anshi Rebellion broke out, and the Tang Dynasty turned from prosperity to decline. In order to face external threats, the Tang Dynasty changed the conscription system to the conscription system, and the separatist regime of the buffer region was extremely serious. The Tang Dynasty could not completely control the forces of the buffer region, so the two sides compromised. In the middle and late Tang Dynasty, the corruption of the imperial examination led to those who had no virtue or talent being given official titles, and those who failed in the list complained bitterly. Coupled with the outbreak of Huang Chao, the Tang Dynasty existed in name only.
Jin Dynasty was established on behalf of Wei and Song Dynasty was established on behalf of Zhou Dynasty. He came to power because the royal family of the previous dynasty declined, and the emperor was too young to control state affairs.
After Sima Yan succeeded to the throne, he believed that the demise of Cao Wei was due to the weakness of imperial power. He enfeoffed many kings with the same surname and made his idiot son emperor, which laid the groundwork for the chaos of the eight kings in the future. After the Eight Kings Rebellion, northern nomads invaded the Central Plains, Di Chin was captured, and the Western Jin Dynasty perished. Si Marui established the Eastern Jin Dynasty in Jiankang, but failed many times in the Northern Expedition. Finally, it was replaced by Liu Yu.
After Zhao Kuangyin acceded to the throne, he learned the experience and lessons of the Tang Dynasty, and the later Zhou Dynasty replaced the later Han Dynasty, including his own. He decided to weaken the power of military commanders, relieve the military power with a glass of wine, and emphasize literature over martial arts. At this time, the strength of Qidan (Liao) reached its peak. After the failure of Zhao Guangyi's Northern Expedition and before the alliance of Single Source, the Song Dynasty was at a disadvantage in the border battle. For the border enemies, the Song Dynasty exchanged China currency for peace. Through the trade surplus, the Song Dynasty even took advantage. Later, the Jin people went south and took Huidi and Qin Emperor away. King Kang and Zhao Jian established the Southern Song Dynasty. During many northern expeditions, no results were achieved, and they were finally destroyed by the Yuan Dynasty.
Jin and Song Dynasties were able to live in a corner of the south of the Yangtze River, in fact, because of the local separatist regime (Three Kingdoms? Wu Dong, Five Dynasties? Southern Tang Dynasty) has established a great foundation, and various facilities in the south of the Yangtze River are almost complete. As the Jin Dynasty closed Du Nan, a large number of Central Plains people moved south, and the south was vigorously developed, which also provided a strong foundation for its continuation.