Tan Chuduan

Originally named Yu, with the courtesy name Boyu, he came from Ninghai in Shandong. He became Wang Chongyang's disciple in 1167 and received the religious name Chuduan. His identity as Changzhenzi connects accounts of the individual teacher with later Quanzhen ancestral remembrance.

After Wang Chongyang's death he was associated with religious life in the Yi and Luo river region. His biography ends at Chaoyuan Temple in Luoyang. The Nanwu branch's reverence for him identifies a lineage relationship; it need not imply that every later institutional form was already established during his life.

Tan was also remembered for calligraphy, particularly renderings of the characters for tortoise and snake that devotees collected. This artistic reputation sits alongside sacred stories of his early life and meeting with Wang Chongyang. The calligraphic tradition provides a way to study his reception beyond a list of dates and honors.