[Why] In the late seventeenth century, Tsarist Russian cavalry crossed Siberia and forcibly invaded the Qing's Heilongjiang basin, building castles like Yaksa and ruthlessly massacring frontier people, seriously threatening the Qing court's northern sovereignty. [What] Emperor Kangxi mobilized troops to launch two Yaksa self-defense counterstrikes, used Red Coat cannons to blast the enemy fortress, and thoroughly subdued the Russian invading army. The two sides then opened equal boundary negotiation at Nerchinsk. [Who] Emperor Kangxi Xuanye was a generation of great emperor of firm sovereignty will and modern-era diplomatic vision. Heilongjiang defenders like Sabsu were the iron-blooded Northeast meritorious officials who bravely resisted Russian invasion. [How] The Treaty of Nerchinsk is the first time in Huaxia history that the China-Russia eastern boundary was clearly drawn under the modern sovereign-state international law framework as an equal agreement. It preserved the vast sovereign frontier defense pattern south of the Outer Khingan Range.
Why
The historic event of Signing of Treaty of Nerchinsk represents a key developmental peak of the Huaxia dynastic system. The historic first boundary treaty negotiated under international legal concepts. By establishing this moral or administrative benchmark, it continues to shape the structural and philosophical fabric of ancient Chinese statecraft.