This term refers to the areas along the middle and lower reaches of the Yellow River where ancient Huaxia (华夏) people or the Han people lived. Originally, the term Zhongguo (中国) meant both this region and its culture. The Huaxia people established their states along the Yellow River. Believing the areas were located in the center of the world, they called it Zhongguo (the Central Country, as against other areas around it). Later, the term was used to refer to the Central Plains in North China and the states founded in that area. Since the Qing Dynasty, Zhongguo has been used to refer specifically to all the territory of China and its sovereignty. Currently, Zhongguo is used as the abbreviated form of the People’s Republic of China.
Give benefit to the people in the capital, and reassure and pacify all the feudal dukes and princes in the country. (The Book of Songs)
If the areas of Wu and Yue (under the control of Sun Quan) could stand up to confront the central region (under the control of Cao Cao), the former should better cut ties with the latter. (The History of the Three Kingdoms)