Some may think it odd that the central Asian empire from circa 400 b. c. to circa 200 a. d. would be named for Kush a son of Ham, the Kushan Empire, yet the Hindu Kush mountains to the south were named for him centuries previously in the days of the Indus Valley Civilization (during the Ice Age), and the white jade bearing Yurungkash river of the Takla Makan Basin was named for him, so the Kushans, Indo European (Japhetic) speakers the Tocharians, called themselves Kuci.