The early Chinese civilization was located between two main rivers, the Yangtze River and the Hung He River, because unlike most of China, the plain between the two rivers is fertile, allowing the people to grow rice and other crops. The rivers provided water for daily life, and, near the Yangtze, the water from mountain run off allowed people to grow rice. The nomads in the northern grasslands became the Mongols and did not develop the sedentary lifestyle of the people who settled on the plain between the rivers. In addition, China was surrounded to the west by mountains and deserts. These geographical features kept China isolated from the rest of the world, allowing its civilization to flourish in isolation from Europe and the rest of the world until the development of the Silk Road.
The early Chinese civilization centered almost entirely around the Yellow River valley as it was a fertile region conveniently accessed by travel on the river and without many geographical barriers. Because of this, it quickly grew and expanded until it filled most of the valley and developed a strong civilization. Along with this valley, the eastern regions of China were able to develop stronger, more permanent civilizations thanks to fertile farmland, unlike more nomadic civilizations to the West in areas that were more arid and difficult to survive in.
The Han people coagulated into a distinct group in what is often referred to as the Chinese Plain, an area of eastern China that included the Yellow River Delta. The agrarian economy was bolstered by internal and then external trade as they expanded their ship-building capacity. Their interactions with the more nomadic cultures to the West helped to build strong trade routes that allowed for trade to expand even further.