[Why] The Qing court long practiced seclusion policy, seriously cut off from the development tide of modern Western industrial revolution. To reverse the trade deficit against China, Britain shamelessly launched the Opium War. [What] The Great Qing Empire under the strong ships and cannons of the West met devastating defeat. The Qing court was forced at Jinghai Temple to sign the unequal Treaty of Nanking, ceding Hong Kong Island, paying huge indemnity, and forced to open ports for trade. [Who] Emperor Daoguang faced industrial civilization with no foresight whatsoever, panicking into compromise and surrender. British plenipotentiary Pottinger was the Western invader who relied on modern industrial military force to extort wantonly and trample national dignity. [How] The signing of the treaty marked classical China being forcibly drawn into the capitalist world market and reduced to a semi-colonial semi-feudal society. It opened the painful grand curtain of modern China's history of humiliation and tragic salvation.
Why
The historic event of Treaty of Nanking represents a key developmental peak of the Huaxia dynastic system. The painful modern collision and the dawn of national humiliation. By establishing this moral or administrative benchmark, it continues to shape the structural and philosophical fabric of ancient Chinese statecraft.