[Why] In the late Gaozong era, the emperor was ill and neglected government, and Empress Wu took the chance to handle state affairs and gradually grasped the absolute axis of central power. The conservative Guanlong aristocratic clans took a hostile and stubbornly obstructive attitude toward her. [What] Wu Zetian, on the strength of strong political strategy, defeated the conservative aristocratic forces and finally proclaimed herself Emperor of the Great Zhou, changing the era and assuming the throne. She vigorously reformed the examination system, created the palace examination, and broke convention to elevate large numbers of commoner civil officials. [Who] Wu Zetian is the only orthodox female emperor in Chinese history, terrifying the world with her supreme tactics and statecraft vision. Worthy ministers like Di Renjie were the court pillars she employed in her late years to preserve the benign transition of the state. [How] Wu Zetian's enthronement greatly shattered the political monopoly of the Guanlong great aristocrats and successfully realized the transfer of power from the great clans to commoner plebeians. She bridged past and future and laid the bureaucratic foundation of High Tang prosperity.
Why
The historic event of Wu Zetian's Reign represents a key developmental peak of the Huaxia dynastic system. The only female emperor in Chinese history who accelerated civil examinations. By establishing this moral or administrative benchmark, it continues to shape the structural and philosophical fabric of ancient Chinese statecraft.