The Tang dynasty, or Tang Empire, was an imperial dynasty of China that ruled from 618 to 907 AD. Historians generally regard the Tang as a high point in Chinese civilization, and a golden age of cosmopolitan culture. From the outset, religion played a role in Tang politics. In his bid for power, Li Yuan had attracted a following by claiming descent from the Taoism sage Lao Tzu. People bidding for office would request the prayers of .