The Qin State became dominan in China BY THE GRADUAL CONQUEST OF OTHER STATES.
Qin rulers conquered every region under the Zhou empire. They also conquered outlying southern regions up to Vietnam and northern regions towards Korea.
The great advantage of the Chinese written language was that it had symbols. The Chinese written language was universally used in all regions and isolated places in china. Although some Chinese groups modified and changed its verbal sounds, they still had the same symbols of the language. Even if the spoken language was different in some places, Chinese people were still able to learn and understand the written language. This language highly helped the people in China easily communicate and unite even with its large land and diverse group of people.
