During the fourth century and the first half of the fifth some twenty ephemeral states, governed by Tartar chieftains and perpetually involved in mutual war, rose and fell in northern China. The most permanent of them was Northern Wei which lasted till 535 A.D. But the Later Chao and both the Earlier and Later Ts'in are important for our purpose[614]. Some writers make it a reproach to Buddhism that its progress, which had been slow among the civilized Chinese, became rapid in the provinces which passed into the hands of these ruder tribes. But the phenomenon is natural and is illustrated by the fact that even now the advance of Christianity is more rapid in Africa than in India. The civilization of China was already old and self-complacent: not devoid of intellectual curiosity and not intolerant, but sceptical of foreign importations and of dealings with the next world. But the Tartars had little of their own in the way of literature and institutions: it was their custom to assimilate the arts and ideas of the civilized nations whom they conquered: the more western tribes had already made the acquaintance of Buddhism in Central Asia and such native notions of religion as they possessed disposed them to treat priests, monks and magicians with respect. Of the states mentioned, the Later Chao was founded by Shih-Lo[615] (273-332), whose territories extended from the Great Wall to the Han and Huai in the South. He showed favour to an Indian monk and diviner called Fo-t'u-ch'êng[616] who lived at his court and he appears to have been himself a Buddhist. At any rate the most eminent of his successors, Shih Chi-lung[617], was an ardent devotee and gave general permission to the population to enter monasteries, which had not been granted previously. This permission is noticeable, for it implies, even at this early date, the theory that a subject of the Emperor has no right to become a monk without his master's leave. In 381 we are told that in north-western China nine-tenths of the inhabitants were Buddhists. In 372 Buddhism was introduced into Korea and accepted as the flower of Chinese civilization. The state known as the Former Ts'in[618] had its nucleus in Shensi, but expanded considerably between 351 and 394 A.D. under the leadership of Fu-Chien[619], who established in it large colonies of Tartars. At first he favoured Confucianism but in 381 became a Buddhist. He was evidently in close touch with the western regions and probably through them with India, for we hear that sixty-two states of Central Asia sent him tribute. The Later Ts'in dynasty (384-417) had its headquarters in Kansu and was founded by vassals of the Former Ts'in. When the power of Fu-Chien collapsed, they succeeded to his possessions and established themselves in Ch'ang-an. Yao-hsing[620], the second monarch of this line was a devout Buddhist, and deserves mention as the patron of Kumârajîva[621], the most eminent of the earlier translators.