What factors contributed to the advanced nature of ancient Chinese civilization? Why was it not able to spread its culture and influence beyond its borders?

China was an unusually stable empire for 2000 years because of its physical isolation from the rest of the world. This allowed it to develop in ways that empires constantly disrupted by foreign invasion could not. So, a number of technologies such as paper, gunpowder, the stirrup, printing, crop rotation were developed first in China, because the stable government there was in a better position to foster them than in more unstable parts of the world. These inventions were indeed spread to the rest of the world, over the course of centuries. However, China’s physical isolation also limited its ability to directly influence the world, in other ways. https://www.quora.com/What-factors-contributed-to-the-advanced-nature-of-ancient-Chinese-civilization-Why-was-it-not-able-to-spread-its-culture-and-influence-beyond-its-borders