 The Ashina belonged to the last Xiongnu princedom destroyed by Xianbei-Toba by AD 439.From Gansu, the Ashina retreated to the Altai, taking with them a number of distinctive ethnographic traits.Chinese sources indicate that the Xiongnu did not have an ideographic form of writing like Chinese, but in the 2nd century BC, a renegade Chinese dignitary Yue "taught the Shanyu to write official letters to the Chinese court on a wooden tablet 31 cm long, and to use a seal and large-sized folder."