Cause & Context
Following Shang Yang's reforms, a powerful Qin expanded eastward, compelling the other six states to forge strategic coalitions for survival against Western hegemony.
Epochal Overview
Su Qin engineered the 'Vertical Alliance' (Hezong) uniting the six eastern states against Qin, while Zhang Yi formulated Qin's 'Horizontal Alliance' (Lianheng), strategically dividing Qi and Chu through diplomacy and deception.
Key Figures
Strategists Su Qin and Zhang Yi steered international diplomacy alongside rivals Gongsun Yan and Fan Ju, transforming the Warring States balance of power.
Civilizational Impact
These alliance networks represented the highest sophistication of ancient Chinese geopolitical theory, enabling Qin to dismantle collective resistance and pave the path toward universal empire.