In 450, Emperor Taiwu once again attacked the Liu Song and reached Guabu (瓜步, in modern Nanjing, Jiangsu), threatening to cross the river to attack Jiankang, the Liu Song capital. Though up to this point, the Northern Wei military forces dominated the Liu Song forces, they took heavy casualties. The Northern Wei forces plundered numerous households before returning north. At this point, followers of the Buddhist Gai Wu (蓋吳) rebelled. After pacifying this rebellion, Emperor Taiwu, under the advice of his Daoist prime minister Cui Hao, proscribed Buddhism, in the first of the Three Disasters of Wu. At this late stage in his life, Emperor Taiwu meted out cruel punishments, which led to his death in 452 at the hands of the eunuch Zong Ai. This sparked off turmoil that only ended with the ascension of Emperor Wencheng later that same year. In the first half of the Northern Wei dynasty (386–534), the Xianbei steppe tribesmen who dominated northern China kept a policy of strict social distinction between them and their Chinese subjects. Chinese were drafted into the bureaucracy, employed as officials to collect taxes, etc. However, the Chinese were kept out of many higher positions of power. They also represented the minority of the populace where centers of power were located. Widespread social and cultural transformation in northern China came with Emperor Xiaowen of Northern Wei (reigned 471–499), whose father was a Xianbei, but whose mother was Chinese. Although of the Tuoba Clan from the Xianbei tribe, Emperor Xiaowen asserted his dual Xianbei-Chinese identity, renaming his own clan after the Chinese "Yuan" (元 meaning "elemental" or "origin"). In the year 493 Emperor Xiaowen instituted a new sinification program that had the Xianbei elites conform to many Chinese standards. These social reforms included donning Chinese clothing (banning Xianbei clothing at court), learning the Chinese language (if under the age of thirty), applied one-character Chinese surnames to Xianbei families, and encouraged the clans of high-ranking Xianbei and Chinese families to intermarry. Emperor Xiaowen also moved the capital city from Pingcheng to one of China's old imperial sites, Luoyang, which had been the capital during the earlier Eastern Han and Western Jin dynasties.