The second dynasty, the loosely feudal Shang, definitely settled along the Yellow River in eastern China from the 18th to the 12th century BCE. They were invaded from the west by the Zhou, who ruled from the 12th to the 5th century BCE. The centralized authority of the Zhou was slowly eroded by warlords. Many strong, independent states continually waged war with each other in the Spring and Autumn period, only occasionally deferring to the Zhou king.
The first unified Chinese state was established by the Qin Dynasty in 221 BCE, when the office of the Emperor was set up and the Chinese language was forcibly standardized. This state did not last long, as its legalist policies soon led to widespread rebellion.
The subsequent Han Dynasty ruled China between 206 BCE and 220 CE, and created a lasting Han cultural identity among its populace that would last to the present day. The Han Dynasty expanded China's territory considerably with military campaigns reaching Korea, Vietnam, Mongolia and Central Asia, and also helped establish the Silk Road in Central Asia.
After Han's collapse, another period of disunion followed, including the highly chivalric period of the Three Kingdoms. Independent Chinese states of this period also opened diplomatic relations with Japan, introducing the Chinese writing system there. In 580 CE, China was reunited under the Sui. However, the Sui Dynasty was...