Qingliang Chengguan (Chinese: 澄觀; pinyin: Chéngguān; Korean: Jinggwan; Japanese: Chōgan, 738–839 or 737-838 CE),[1] was an important scholar-monk and patriarch of the Huayan school of Chinese Buddhism also known as Huayan pusa (bodhisattva Avatamsaka) and Qingliang Guoshi (Imperial Preceptor "Clear and Cool", Clear and Cool is a name for Mount Wutai).[2][3]
Chengguan is most widely known for his extensive commentaries and sub-commentaries to the Avataṃsaka Sūtra (Huayan jing), as well as for his translation of a new Gandhavyuha sutra version, together with the Indian monk Prajña.[2][3] Chengguan's commentaries on the Avataṃsaka quickly became one of the authoritative sources for Huayan doctrine.[3] Chengguan lived through the reigns of nine emperors and was an honored teacher to seven emperors starting with Xuanzong (玄宗) until Wenzong (文宗).[3] Chengguan was also the teacher of the influential Huayan patriarch Zongmi.[2][3]