The First Emperor left the legacy of an energetic, but bloody, monarchy to Chinese historians. And this is no doubt why the Qin Dynasty could not survive it. It is replaced by the long Han Dynasty, dominating China for more than four centuries from 206 BC to 220 AD. The Empire continues to encompass the basins of the two great rivers, and even extends to the south as far as Canton and to the west into the corridor of the Silk Road, nearly to Bactria. But the demographic and economic center of gravity remains in the north. The census of the year 2 AD showed 85% of China’s 57 million people to be in the north. The most populated zones[408] are the Wei valley, ancient nursery of the Qin, and the vast alluvial plain of the lower course of the Yellow River down to the sea, between the Jiang River to the north and the Huai to the south. The capital of the early Han, Chang’an, is on the present-day site of Xi’an. Following a temporary usurpation of power by a dignitary named Wang Mang (9 to 23 AD), the capital is relocated to
Luoyang, near the ancient capital of the Zhou (the latter Han), where the Yellow River flows out onto the plain.
