The Kung-sun that follows his surname indicates that he was descended from some feudal lord in the old times of the Chow dynasty.

We know indeed of no ruling house which had the surname of Foo, but its adoption by the grandson of a ruler can be satisfactorily accounted for; and his posterity continued to call themselves Kung-sun, duke or lord's grandson, and so retain the memory of the rank of their ancestor.
(11) Whom they had left behind them at T'un-hwang.
(12) The country of the Ouighurs, the district around the modern Turfan or Tangut.
(13) Yu-teen is better known as Khoten.

Dr.P.Smith gives (p.

11) the following description of it:--"A large district on the south-west of the desert of Gobi, embracing all the country south of Oksu and Yarkand, along the northern base of the Kwun-lun mountains, for more than 300 miles from east to west.

The town of the same name, now called Ilchi, is in an extensive plain on the Khoten river, in lat.
37d N., and lon.