[Why] After Tang's death, the new king Tai Jia governed cruelly and willfully shattered the founding code and ritual order. The very framework of court discipline was at risk of full collapse and the central authority slid into severe turmoil. [What] Driven by his loyalty to the Shang state, the regent minister Yi Yin resolutely exiled Tai Jia to the Tong Palace to compel his repentance. Tai Jia repented sincerely at Tong, after which Yi Yin personally welcomed him back to the capital and returned the throne. [Who] Yi Yin is the first great minister in Chinese political history to place the welfare of the state above the king and to constrain royal power. Tai Jia underwent a moral conversion from foolish ruler to law-abiding sovereign attentive to remonstrance. [How] The episode created the earliest moral template of sage-ministerial regency and royal-power restraint, with profound influence on later politics. It demonstrated that even in early society, royal authority had to be bound by morality and legitimate order.
Why
The historic event of Yi Yin Banishing Tai Jia represents a key developmental peak of the Huaxia dynastic system. The earliest moral paradigm of sage ministership and check on monarchical power. By establishing this moral or administrative benchmark, it continues to shape the structural and philosophical fabric of ancient Chinese statecraft.