The first of China's legendary Five Emperors, the Yellow Emperor, or Huangdi, supposedly reigned from 2697 BCE; among his many accomplishments, Huangdi has been credited with the invention of the principles of traditional Chinese medicine. (According to the writings in the Shiji by historian Sima Qian [145 BC-90 BCE], the reign of Huangdi, or the Yellow Emperor, lasts until his death in 2598 BCE.)