Khotan traces its history back at least as far as the 3rd century BCE, when the eldest son of the Indian emperor Asoka is said to have settled here. It was of great importance on the Silk Road, and is claimed to have been the first place outside China to have cultivated silk. It sits astride the Karakash or ˉBlack Jadeˇ and Yurungkash or ˉWhite Jadeˇ Rivers, which here conjoin to form the Khotan Darya, and has been famous for its jade for well over two millennia. In times past trade routes crossed the desert to the north all the way to Kuqa, and as recently as 2007 this link has been re-established for the first time in centuries with the opening of a second Desert Highway leading to Aksu, distant some 424km to the north. In 1006 Khotan was conquered by Uighur Muslims from Kashgar, and since that time the city remains a very Uighur place.