was wiped out. North China was ruled by Shi Le's Later Zhao dynasty for the next 20 years. However, the "Liu" Xiongnu remained active in the north for at least another century. Tiefu tribe and Hu Xia dynasty (260–431) The northern Tiefu branch of the Xiongnu gained control of what is modern-day Inner Mongolia in the 10 years between the conquest of the Xianbei-ruled state of Dai by the Former Qin dynasty in 376, and its restoration in 386 as the Northern Wei dynasty. After 386, the Tiefu were gradually destroyed by or surrendered to the Tuoba, with the submitting Tiefu becoming known as the Dugu. Liu Bobo, a surviving prince of the Tiefu fled to the Ordos Loop, where he founded a state called the Hu Xia dynasty (thus named because of the Xiongnu's supposed ancestry from the Xia dynasty) and changed his surname to Helian (赫連). The Hu Xia dynasty was conquered by the Northern Wei in 428–31, and the Xiongnu thenceforth effectively ceased to play a major role in Chinese history, assimilating into the Xianbei and Han ethnicities. Tongwancheng (meaning "Unite All Nations") was the capital of the Hu Xia, whose rulers claimed descent from Modu Chanyu. The ruined city was discovered in 1996 and the State Council designated it as a cultural relic under top state protection. The repair of the Yong'an Platform, where Helian Bobo, emperor of the Da Xia regime, reviewed parading troops, has been finished and restoration on the 31-meter-tall turret follows. Juqu clan and Northern Liang dynasty (401–460) The Juqu clan was of Lushuihu origin, a branch of the Xiongnu. Their leader Juqu Mengxun took over the Northern Liang dynasty by overthrowing the former puppet ruler Duan Ye. By 439, the Juqu power was destroyed by the Northern Wei dynasty. Their remnants were then settled in the city of Gaochang before being destroyed by the Rouran. Significance The Xiongnu confederation was unusually long-lived for a steppe empire. The purpose of raiding the Central Plain was not simply for goods, but to force the Central Plain polity to pay regular tribute. The power of the Xiongnu ruler was based on his control of Han tribute which he used to reward his supporters. The Han and Xiongnu empires rose at the same time because the Xiongnu state depended on Han tribute. A major Xiongnu weakness was the custom of lateral succession. If a dead