[SolaceQuantum]

If you look on the wikipedia page, a "true" unification of China as people identified as Chinese didn't occur until about the revolution in China, where it was necessary for a strong centralized government to control all of China. Beforehand it was more considered like warring states, each culture very distinct. Some of it still remains today.

[seanmcdirmid]

If that's the case, then China still isn't unified. The emperor was a strong central government, but, which is true even today, often "tian gao, haungdi yuan."

Warring state periods did occur during history, but stable and strong political unions were the norm in most of the dynasties.