[Why] Sui unification reorganized the political and geographic pattern of the realm, but the old Guanzhong base was now severely cut off from the increasingly prosperous Jiangnan economic engine. The empire urgently needed a strategic control pivot in the east. [What] Emperor Yang of Sui mobilized millions of laborers to build the grand metropolis of Eastern Capital Luoyang on the well-situated Luoyang plain. The new city was orderly and bustling, becoming a vast administrative and logistical center commanding the empire. [Who] Emperor Yang of Sui was a pioneer monarch pursuing imperial architectural grandeur and geographic absolutism. Tens of thousands of craftsmen who died of long journey and brutal corvee were the foundation of this epic of construction. [How] The construction of Eastern Luoyang marked the successful realization of the strategic eastward and southward migration of political center of gravity in the Sui-Tang medieval period. It greatly elevated the empire court's material logistical and pacification mobility.
Why
The historic event of Construction of Eastern Capital Luoyang represents a key developmental peak of the Huaxia dynastic system. A massive urban planning epic reflecting Sui's unparalleled mobilization power. By establishing this moral or administrative benchmark, it continues to shape the structural and philosophical fabric of ancient Chinese statecraft.