This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
When the Tang dynasty was founded in 618, its ruling Li family made an unusual claim for a new imperial house: descent, in a direct line, from Laozi himself, the sage credited with founding Taoism centuries before. That genealogical claim carried real institutional weight, and the Tang elevated Taoism to the highest official standing it would ever hold in Chinese history.
Emperor Gaozong put that elevation into the machinery of the state directly, adding the Tao Te Ching to the required classics of the imperial examination system, the same system that trained and selected every official who would go on to administer the empire. A text of religious philosophy became, for the length of the dynasty, part of what a Tang bureaucrat had to master to hold office at all.
Taoism did not hold the field alone. Confucianism remained the framework of imperial administration and social order, and Buddhism, imported centuries earlier, was growing rapidly in popularity and patronage across the same period. Taoism competed with both throughout the dynasty rather than displacing either, but its position as the ruling house's own ancestral faith gave it a standing neither rival could claim, and that standing held until the Tang itself collapsed in 907.
What the Tang elevation changed for Taoism's spread was proof that a Chinese imperial house would build its own legitimacy around Taoist descent rather than treating the faith as one court patronage among several. Three centuries of that standing, backed by the examination system itself, spread Taoist texts and Taoist prestige across the empire's own governing class in a way no earlier period had matched.