Imperial China is a period of Chinese history. It lasted over 2,000 years. It began with Qin Shi Huang's uniting of China under the Qin dynasty in 221 BC. It ended with the overthrow of the Qing dynasty in 1911. Throughout this period, many features of Chinese civilization spread throughout all of China. These included Confucianism, standardized testing, standardized weights and counting systems, trade routes, and Chinese characters. China became known worldwide for all these features.