The Development of Daoism in the Tang Dynasty

Advancements in Taoist Theory
With the strong advocacy of the Tang royal family, studying the thoughts of Laozi and Zhuangzi became a prevalent trend. At that time, princes, ministers, Confucian scholars, and Taoists all engaged in researching and annotating Laozi (Tao Te Ching) and Zhuangzi. There were also many theoretical works influenced by Lao-Zhuang thought, especially the "Chongxuan School" (School of Double Mystery) represented by Cheng Xuanying and Li Rong, which exerted a profound impact on the development of Taoist theory both at that time and thereafter.

Publication of the Taoist Canon
The Tang Dynasty continued to collect and sort out Taoist scriptures. During the Kaiyuan era (713–741), a comprehensive collection of Taoist texts was compiled, known as the Kaiyuan Daozang (Kaiyuan Taoist Canon). In the 7th year of the Tianbao era (748), an imperial edict was issued to transcribe and widely circulate it, making it the first Taoist canon in Chinese history.

Systematic Development of Taoist Rituals
Taoist rituals had already taken initial shape during the Southern Dynasties under Lu Xiujing. In the Tang Dynasty, Taoists such as Zhang Wanfu, Zhang Jixian, and Du Guangting (of the late Tang and Five Dynasties period) systematically organized, added to, and revised Taoist rituals, as well as the transmission of scriptures, precepts, and talismans, making them more enriched and complete.

Evolution of Neidan (Inner Alchemy) Taoism
In the Tang Dynasty, alchemical practices began to shift from waidan (outer alchemy) to neidan (inner alchemy). During this period, neidan already had a considerable influence, with Zhong Lizhong (Han Zhongli) and Lü Dongbin being the most renowned advocates. The inner alchemy cultivation methods they promoted were called "Zhong-Lü Golden Elixir Taoism," and the Quanzhen School (Complete Perfection School) in later generations revered Zhong and Lü as their patriarchs.

Expansion of Taoist Temples
Taoist temples in the Tang Dynasty were almost ubiquitous across famous mountains and major cities. According to a record by Du Guangting dated the 15th day of the 12th lunar month in the 4th year of the Zhonghe era (884), since the founding of the Tang Dynasty, "approximately 1,900 temples had been built, and over 15,000 Taoists had been ordained. This does not include the temples converted from the mansions or estates of princes, imperial princesses, nobles, officials, or commoners."

Rise of Taoist Sects
In the Tang Dynasty, the largest Taoist sect was the Maoshan School, followed by the Louguan School. Additionally, during the mid-to-late Tang Dynasty, the Longhu Mountain Tianshi Dao (Celestial Master Taoism), which claimed descent from Zhang Daoling, gradually took shape, known as the "Longhu Sect." With imperial support, this sect grew rapidly, laying the foundation for the prosperity of Longhu Mountain Tianshi Dao in the Song, Yuan, and subsequent dynasties.