The Eight Immortals did not emerge as a group until the Yuan dynasty (1279-1368 CE). It is doubtful if they were indeed historical figures. Each of them has a personal mythology traceable to the Han (200 BCE- 220 CE) and Song (960-1279 CE) dynasties. They are also associated with Eight Trigram directions in the Classic of Change or Yijing 易经. Identified by his castanets and princely robe, Cao Guojiu 曹国舅 was a former aristocrat. He retreated into the mountains to cultivate the Dao after being disenchanted with the world. When asked by Lü Dongbin and Zhong Liquan to locate the Dao which he cultivated, he replied that it was within in his heart.
