The Zhang Heng 张恒

Zhang Heng, the 12th Heavenly Master of the Zhengyi School (a major school of Taoism). His courtesy name was Derun, and he was the eldest son of Zhang Tongxuan.

He had a profound mastery of Confucian classics, historical records, and Confucian works, with an exceptional memory that allowed him to retain whatever he read. He was particularly skilled in Taoist illusionary arts. Emperor Gaozong of the Tang Dynasty summoned him and asked about the way to govern the state and bring peace to the people. Zhang Heng replied, "If one can practice wu-wei (non-action in accordance with the Dao), the world will be well-governed." Emperor Gaozong greatly appreciated this answer

He passed away at the age of 98. In the 13th year of the Zhizheng era (1353) of Emperor Shun of the Yuan Dynasty, he was posthumously awarded the title of "Shangqing Xuande Taihe True Lord".

(From Han Tianshi Shijia (Genealogy of the Heavenly Masters of the Han Dynasty))