[Why] In the late Shang, King Di Xin (Zhou) inherited a dynasty at its financial and military peak. But he gradually sank into personal indulgence, sharpened conflict with the rising western Zhou, and exiled honest counsel from his court. [What] Zhou built the Lutai Terrace and the famed Pools-of-Wine and Forests-of-Meat to squander the treasury. He cut out the heart of his uncle Bi Gan, imprisoned Ji Zi, employed flatterers like Fei Zhong and E Lai, and waged ruinous wars against the eastern Yi to drain the state. [Who] King Zhou of Shang stands alongside Jie of Xia as the archetypal Chinese tyrant, both martial prowess and savage cruelty in one person. Bi Gan, Ji Zi, and Wei Zi were the three loyal and principled noble worthies of late Shang. [How] Zhou's tyranny destroyed the social foundation of Shang and turned the hearts of the people decisively toward the Zhou tribe. It laid the irreversible political groundwork for the Battle of Muye and the fall of Shang.
Why
The historic event of Tyranny of King Zhou represents a key developmental peak of the Huaxia dynastic system. Shang's apex reversed into political collapse by the cruelty of its final king. By establishing this moral or administrative benchmark, it continues to shape the structural and philosophical fabric of ancient Chinese statecraft.