Iron Fist was an Iron Fist in the 11th century China.
Lin Youlan was part of the Lin family in China during the 11th century. When the emperor called for one man from each family to serve in his army, Youlan's sister disguised herself as man to serve in their father's stead as he was too old to fight.
During this time, Youlan's father was killed by Hydra. After her sister returned, she was summoned to become the Emperor's concubine. Youlan's sister told her that she had been recruited by K'un-Lun and told Youlan to seek them out, before killing herself to avoid becoming a concubine.
In K'un-Lun, Youlan trained K-un-Lun to avenge her father and sister and became the Iron Fist.
In the present, Youlan's descendant was captured by AIM and forced to relive her memories.