Fu Chien’s state showed another innovation:  the armies of the Huns and the Hsien-pi had consisted entirely of cavalry, for the nomads of the north were, of course, horsemen; to fight on foot was in their eyes not only contrary to custom but contemptible.  So long as a state consisted only of a league of tribes, it was simply out of the question to transform part of the army into infantry.  Fu Chien, however, with his military organization that paid no attention to the tribal element, created an infantry in addition to the great cavalry units, recruiting for it large numbers of Chinese.  The infantry proved extremely valuable, especially in the fighting in the plains of north China and in laying siege to fortified towns.  Fu Chien thus very quickly achieved military predominance over the neighbouring states.  As we have seen already, he annexed the “Earlier Yen” realm of the proto-Mongols (370), but he also annihilated the Chinese “Earlier Liang” realm (376) and in the same year the small Turkish Toba realm.  This made him supreme over all north China and stronger than any alien ruler before him.  He had in his possession both the ancient capitals, Ch’ang-an and Loyang; the whole of the rich agricultural regions of north China belonged to him; he also controlled the routes to Turkestan.  He himself had had a Chinese education, and he attracted Chinese to his court; he protected the Buddhists; and he tried in every way to make the whole country culturally Chinese.  As soon as Fu Chien had all north China in his power, as Liu Yuean and his Huns had done before him, he resolved, like Liu Yuean, to make every effort to gain the mastery over all China, to become emperor of China.  Liu Yuean’s successors had not had the capacity for which such a venture called; Fu Chien was to fail in it for other reasons.  Yet, from a military point of view, his chances were not bad.  He had far more soldiers under his command than the Chinese “Eastern Chin dynasty” which ruled the south, and his troops were undoubtedly better.  In the time of the founder of the Tibetan dynasty the southern empire had been utterly defeated by his troops (354), and the south Chinese were no stronger now.

Against them the north had these assets:  the possession of the best northern tillage, the control of the trade routes, and “Chinese” culture and administration.  At the time, however, these represented only potentialities and not tangible realities.  It would have taken ten to twenty years to restore the capacities of the north after its devastation in many wars, to reorganize commerce, and to set up a really reliable administration, and thus to interlock the various elements and consolidate the various tribes.  But as early as 383 Fu Chien started his great campaign against the south, with an army of something like a million men.  At first the advance went well.  The horsemen from the north, however, were men of the mountain country, and in the soggy plains of the Yangtze region, cut up by hundreds of water-courses