In the past, the "Classic of Poetry" and "Classic of History" recorded the stories of Yu Shun and Xia Yu, who built up a solid reputation by governing well and showing filial piety, serving as officials for a long time before finally becoming emperors decades later. The kings of the Yin and Zhou dynasties also started from people like Yi Yin and Ji, cultivating themselves and doing good deeds, and it took more than ten generations before they finally unified China under King Tang and King Wu. It shows how incredibly difficult it was to achieve this through virtue alone!
After Qin Shi Huang unified the six states, he feared repeating the collapse of the Zhou dynasty. He believed the downfall of the Zhou was due to the interference of hermits, internal struggles among the vassals, invasions by minority ethnic groups, and ultimately being defeated by others. Therefore, Qin Shi Huang abolished the system of noble titles, dismantled cities and destroyed weapons, banned speech and burned books, and suppressed dissent and intellectual opposition. He attacked the Xiongnu and Baiyue externally, establishing a strong ruling power with the aim of bringing peace to the world. However, a powerful enemy suddenly emerged a dozen years later. The border soldiers were even more formidable than the Five Hegemons of the Spring and Autumn period. The common people were forced by outsiders and had no choice but to pick up weapons to resist. Ironically, Qin's harsh rule inadvertently strengthened the very rebels who would overthrow it, ultimately leading to the downfall of the Qin dynasty. Therefore, the Han dynasty overthrew the Qin dynasty, relying solely on Liu Bang, who established his imperial power in just five years, which was remarkably swift. Why? Because the succession of ancient dynasties typically inherited the good situation left by the previous sage kings, while the Han dynasty directly cleaned up the mess left by the Qin dynasty. It's always easier to tear something down than to build it up, right?
So, after the establishment of the Han dynasty, here's a list of the eighteen emperors from Liu Bang's descendants, showing their reigns (in years) after the unification of China. Until Emperor Wen of Han, all the princes and kings who weren't from the Liu family were wiped out. (Table omitted here)
