During the reign of Qin Shi Huang, the six kingdoms were unified, and before that, Xia, Shang, Zhou and other countries adopted a sub-feudal system, and the princes and princes all had their own fiefs and armies, lands and people. Enjoying great power in their own fiefdoms, because the various princes had relatively large rights in their own territory, the strength of the princes in the later period was getting stronger and stronger, and the strength of the Son of Heaven was getting weaker and weaker, and these princely states were subject to each other, and initially the Great Zhou Divided into hundreds of princely states, and in the late Warring States period, only seven relatively large princely states remained.
The Qi ChuYan, Zhao Han, Wei Qin, as we know, would not have been for the fact that the Qin State swept across the world with the wind and clouds and annexed the Six Kingdoms and unified the whole country. China today, like Europe, may be scattered into countless small countries.
Qin Shi Huang unified the six kingdoms, his merits are beyond doubt, it can be said that he is an emperor throughout the ages. Although his tyranny is unacceptable to the world, his contribution to the Chinese nation cannot be erased. It can be said that Qin Shi Huang set an example for future generations, that is, to unify the whole country, which directly affected the history of the Chinese nation for thousands of years.
After Qin Shi Huang destroyed the Six Kingdoms, he sent the great general Meng Tian to lead 300,000 troops to attack the Xiongnu in the north, and Meng Tian was a general of the Gate Family, which won the trust of Qin Shi Huang, and Meng Tian was undoubtedly the right and left arm of Qin Shi Huang, Qin Shi Huang was brilliant, and the remaining Six Kingdoms were not Qin Shi Huang's opponents at all.
Qin Shi Huang's feat of unifying the Six Kingdoms made them dare not act rashly, and at this time, Xiang Yu, the king of Western Chu, was only a member of the nobles of the Six Kingdoms, and the country was destroyed, but he did not dare to face this first person who unified the Six Kingdoms.
As for Liu Bang, the ancestor of Han Gao, at this time, he was still a pavilion chief of the Qin Dynasty, running for food and clothing every day, without lofty ambitions, let alone thinking that many years later he would be able to replace Qin Shi Huang and become the supreme ruler of the world.
In addition to the 300,000 troops of the Qin Dynasty, there were also 500,000 troops of the Southern Expedition to Baiyue, these were only border defense troops, and Xiang Yu only had 3,000 Jiangdong disciples in his hands, Liu Bang did not have soldiers and horses, and the huge gap in strength made Xiang Yu and Liu Bang unable to rise to any thought of resistance.
Moreover, at this time, the generals of the Qin Dynasty who destroyed the Six Kingdoms were basically there, and the so-called soldiers were strong and strong, and the talents were abundant. The tyranny practiced by Qin Shi Huang in his later years made the people miserable, and he built the Great Wall and the Afang Palace. The people of the Qin Dynasty paid heavy taxes and lost the hearts of the people. However, the strength of the Qin Dynasty was still there, and there was still a sense of reverence for this person who unified the six kingdoms, so he did not dare to oppose it.
After the death of Qin Shi Huang, Zhao Gao successfully destroyed the entire Qin state with his own hands, from the army to the court, he removed the pillars of the Qin state one by one, many of the generals who destroyed the Six Kingdoms of Qin either died or fled, the army was scattered, so that the Qin Dynasty was weakening step by step, that is, in this context, the Western Chu overlord Xiang Yu and Liu Bang began to appear on the stage of history, and the Qin Dynasty began to withdraw.