4 _Sociological analysis of the two great alien empires_ The two great empires of north China at the time of its division had been founded by non-Chinese--the first by the Hun Liu Yüan, the second by the Tibetan Fu Chien. Both rulers went to work on the same principle of trying to build up truly "Chinese" empires, but the traditions of Huns and Tibetans differed, and the two experiments turned out differently. Both failed, but not for the same reasons and not with the same results. The Hun Liu Yüan was the ruler of a league of feudal tribes, which was expected to take its place as an upper class above the unchanged Chinese agricultural population with its system of officials and gentry. But Liu Yüan's successors were national reactionaries who stood for the maintenance of the nomad life against that new plan of transition to a feudal class of urban nobles ruling an agrarian population. Liu Yüan's more far-seeing policy was abandoned, with the result that the Huns were no longer in a position to rule an immense agrarian territory, and the empire soon disintegrated. For the various Hun tribes this failure meant falling back into political insignificance, but they were able to maintain their national character and existence. Fu Chien, as a Tibetan, was a militarist and soldier, in accordance with the past of the Tibetans. Under him were grouped Tibetans without tribal chieftains; the great mass of Chinese; and dispersed remnants of tribes of Huns, Hsien-pi, and others. His organization was militaristic and, outside the military sphere, a militaristic bureaucracy. The Chinese gentry, so far as they still existed, preferred to work with him rather than with the feudalist Huns. These gentry probably supported Fu Chien's southern campaign, for, in consequence of the wide ramifications of their families, it was to their interest that China should form a single economic unit. They were, of course, equally ready to work with another group, one of southern Chinese, to attain the same end by other means, if those means should prove more advantageous: thus the gentry were not a reliable asset, but were always ready to break faith. Among other things, Fu Chien's southern campaign was wrecked by that faithlessness. When an essentially military state suffers military defeat, it can only go to pieces. This explains the disintegration of that great empire within a single year into so many diminutive states, as already described. 5 _Sociological analysis of the petty States_ The states that took the place of Fu Chien's empire, those many diminutive states (the Chinese speak of the period of the Sixteen Kingdoms), may be divided from the economic point of view into two groups--trading states and warrior states; sociologically they also fall into two groups, tribal states and military states.