By Han times -- as seen in Sima Qian 's account in the Shiji -- the Yellow Emperor had become a historical ruler whose descendants were thought to have founded the Xia .
The Yellow Emperor as lord of the underworld had been symbolically linked to the Xia .
By Han times -- as seen in Sima Qian 's account in the Shiji -- the Yellow Emperor , who as lord of the underworld had been symbolically linked to the Xia , had become a historical ruler whose descendants were thought to have founded the Xia .