leader, Bai Chengfu, who was reportedly so wealthy that "his horses had silver mangers". With that stolen wealth, which included an abundance of property and thousands of fine horses, Liu established the Later Han (947-950), the shortest dynasty in Chinese history, lasting only four years. The incident took away the central leadership and removed any possibility for the Xianbei to restore the Tuyühu Empire. Western Xia Empire The Western Xia Empire inherited the political and social structures of the Tang and further developed an outstanding civilization characterized as "shining and sparkling". It became the new kingdom for the descendants of the Tuyühu Xianbei who had lost their country. The Western Xia made significant achievements in literature, art, music, architecture, and chemistry. Through effective military organizations that integrated cavalry, chariots, archery, shields, artillery (cannons carried on the back of camels), and amphibious troops for combats on the land and water, the Xia army maintained a powerful stance in opposition to the Song, Liao (916-1125), and Jin (1115–1234) empires to its east, the last of which was founded by the Jurchens, who were the predecessors of the Manchus who would found the Qing Dynasty (1644–1912). The Xia territory encompassed the present Ningxia, Gansu, eastern Qinghai, northern Shaanxi, northeastern Xinjiang, southwest Inner Mongolia, and southernmost Outer Mongolia, spanning about 800,000 square kilometers. In the beginning of the thirteenth century, Genghis Khan unified the northern grasslands of Mongolia and led the Mongol troops to carry out six rounds of attacks against Western Xia over a period of twenty-two years. As Western Xia resisted vehemently, more and more of its people crossed the Qilian Mountains to join the earlier establishments in Qinghai and Gansu in order to avoid the Mongol assaults, which gave rise to the current settlements of the Monguor. During the last round of attacks, Genghis Khan died in Western Xia. The official Mongol historical account attributed his death to an illness, whereas legends told that he died from a wound inflicted in the battles. After the Xia capital was overrun in 1227, the Mongols destroyed much of hu its architecture and written records, killing the last emperor and massacring tens of thousands of civilians. The Xia troops were later incorporated into the Mongol army in their subsequent military conquests in central and southern China. Due to the fierce resistance of the Xia against the Mongol attacks, especially in causing the death of