The aim of this thesis is to explore the life of Cheng Xuanying [special characters omitted] (ca.600--690), a prominent Daoist of the early Tang ? court known for his Sub-commentary on Zhuangzi (Zhuangzi shu [special characters omitted]), of particular interest is Cheng's career in the court eventual exile. I shall explore the politico-religious climate of the early Tang in an attempt to deduce what actions and ideas lead to Cheng Xuanying's sentence and what affect it had on his later life and work.