Yu the Great succeeded in controlling the floods, earning widespread support among the people, and succeeded Shun as the leader of the tribal alliance, at a time when clan society had already reached its late stage. As productivity developed, people produced more than enough to sustain themselves, leaving a surplus. The leaders of clan tribes used their authority to turn this surplus into private property, thus giving rise to private ownership. Tribal leaders amassed great social wealth and became aristocrats. With the increase in surplus goods, tribes frequently waged wars to seize social wealth. Prisoners of war were no longer killed but were brought back and turned into the private property of the aristocrats—slaves—gradually forming two classes: slaves and slave owners, pushing clan society to the brink of collapse.
Yu himself was a great aristocrat. During his lifetime, he owned thousands of slaves and countless cattle and sheep, and his family had become an immensely powerful noble clan. It is said that in his old age, Yu went on an inspection tour to the east and summoned the leaders of various tribes at Mount Kuaiji (in present-day Shaoxing, Zhejiang). The leaders who responded to the summons numbered as many as "ten thousand states," and they all arrived bearing jade and silk. However, the leader of the Fangfeng tribe did not come. Yu considered this a grave disrespect to himself and ordered the execution of the Fangfeng leader. From this, it can be seen that in his later years, Yu was no longer merely the leader of a tribal alliance but a true king.
When Yu grew old, following the abdication system like Yao and Shun, he selected Bo Yi, who had assisted him in flood control, as his successor. However, Bo Yi died early, and since Yu's Xia tribe had many powerful nobles, after Yu's passing, they supported Yu's son Qi to inherit Yu's position. From then on, the abdication system of clan society was formally abolished, and the era of "the world is for all" in the "Great Harmony" society transitioned into a "family under heaven" system where the world belonged to one family.
He named the dynasty he established after his own tribe, Xia, and thus the first slave-owning dynasty in Chinese history—the Xia Dynasty—came into being. However, strictly speaking, Yu was the founding ruler of the Xia Dynasty and also the creator of the slave society.
In the early days of the Xia Dynasty's establishment, its rule was far from stable. Qi summoned and feasted the leaders of various tribes, hoping to gain their recognition of his newly founded dynasty. However, these tribal leaders still adhered to the ancient tradition of public succession, believing that leadership should be held by the most capable person. They saw Qi's actions as treating the realm as his own family's property, which greatly displeased them. Among them, the leader of the Youhu tribe refused to attend the banquet. Enraged, Qi launched a military campaign against the Youhu tribe. The two sides engaged in a fierce battle at a place called Gan, resulting in the Youhu tribe's defeat and the extermination of their entire clan. This battle greatly intimidated the other tribal leaders, who dared not voice any further objections and expressed their willingness to submit to Xia.
The leaders of each tribe were enfeoffed as rulers of their own tribes, and their states were designated as vassal states, which were under the command of the Xia Dynasty and revered the Xia as supreme, annually offering cattle, sheep, grain, and slaves as tribute. In this way, a compulsory state system was established, and the status of the Xia Dynasty was consolidated.
At the beginning of slave society, although some people were freed from labor, slaves were forced to work collectively under the slave owners, which actually increased productivity. Soon, the Xia Dynasty experienced a period of prosperity. All surrounding regions submitted to its rule, and society was stable. However, Qi gradually became arrogant, indulgent, and pleasure-seeking, neglecting state affairs, and died after only ten years on the throne. After Qi's death, his five sons all sought to succeed him, leading to a fierce power struggle within the royal family. After intense competition, Qi's son Tai Kang emerged victorious and became the new ruler. Upon taking the throne, Tai Kang believed he could rest easy and do as he pleased, again ignoring national matters, indulging in sensual pleasures, hunting excessively every day, and refusing to listen to any advice. The internal power struggles within the Xia had already caused government affairs to fall into disarray, yet Tai Kang remained unambitious and debauched, gradually causing court officials to lose hope and the people to become alienated.
At that time, there was a Dongyi tribe called Youqiong in the lower reaches of the Yellow River, whose leader Houyi was an ambitious man. The tribe's ancestor Yi was an incredibly strong divine archer. According to legend, in ancient times, there were ten suns in the sky, all sons of the Heavenly Emperor, who took turns appearing one each day, so people only saw one sun. But one day, the ten suns mischievously appeared together in the sky. Instantly, crops and animals on earth were scorched to death, and rivers, lakes, and seas dried up. The Heavenly Emperor sent Yi to teach these ten children a lesson. Yi drew his bow, nocked an arrow, and shot nine arrows in succession, bringing down nine suns. Immediately, sweet dew fell from the sky, and everything returned to normal.
The incompetence and debauchery of Tai Kang gave other feudal lords an opportunity to seize power and usurp the throne; Hou Yi, seeing that Tai Kang's reckless behavior had caused widespread discontent, sensed an opening and bided his time to replace him.
One day, Tai Kang took his close followers to hunt on the northern bank of the Luo River, staying away for over a hundred days, during which he completely ignored state affairs. When Hou Yi learned of this, he was secretly delighted, seeing it as a perfect opportunity, so he raised an army to occupy the Xia capital, Anyi, and stationed troops on the southern bank of the Luo River. After enjoying himself thoroughly, Tai Kang planned to return, but upon reaching the Luo River, he found heavy forces gathered on the southern bank and panicked, quickly sending someone to inquire what was happening. His scout brought back news that Hou Yi had led his army under the pretext of "punishing the unjust" to drive him out. The tribal leaders, already dissatisfied with Tai Kang and wary of Hou Yi's forces, sent no troops to rescue him. Thus, Tai Kang could not return home and, filled with regret, began a life of exile on the northern bank—this is known in history as "Tai Kang's Loss of the Kingdom." Tai Kang wandered in exile for 27 years before dying of illness in Yangxia.
Hou Yi expelled Tai Kang but still dared not claim the throne himself, so he installed Tai Kang's younger brother Zhong Kang as king, intending to hold real power while making Zhong Kang a puppet. Unwilling to be manipulated, Zhong Kang plotted to weaken Hou Yi's influence and reclaim authority, but the plan was exposed, leading to his house arrest by Hou Yi. Later, he fell ill from depression and eventually died of illness.
After Zhong Kang died, his son Xiang should have succeeded to the throne, but Xiang was still young, so Hou Yi simply drove Xiang away and seated himself on the royal throne, thus the Xia Dynasty changed its ruler. The Xia Dynasty had just begun the system of hereditary succession, but after only two generations of kings, supreme power fell into the hands of someone from a different clan.