Ancient Chinese civilization extended back nearly 4,000 years and was ruled by a succession of dynasties. Key dynasties included the Xia, Shang, Zhou, Qin, and Han dynasties. The Han Dynasty ruled for 400 years and made important contributions such as developing the Silk Road, expanding trade, and establishing a strong central government. Chinese philosophy and religion also developed, with Confucianism, Daoism, and Buddhism influencing Chinese thought and culture.