Typically, such federations exhibited two tendencies. In the case of the Hsiung-nu we indicated already previously that the leader of the federation repeatedly attempted to build up a kind of bureaucratic system, using his bondsmen as a nucleus. A second tendency was to replace the original tribal leaders by members of the family of the federation leader. If this initial step, usually first taken when "outer tribes" were incorporated, was successful, a reorganization was attempted: instead of using tribal units in war, military units on the basis of "Groups of Hundred", "Groups of Thousand", etc., were created and the original tribes were dissolved into military regiments. In the course of time, and especially at the time of the dissolution of a federation, these military units had gained social coherence and appeared to be tribes again; we are probably correct in assuming that all "tribes" which we find from this time on were already "secondary" tribes of this type. A secondary tribe often took its name from its leader, but it could also revive an earlier "primary tribe" name.
The Toba represented a good example for this "cone" structure of pastoral society. Also the Hsiung-nu of this time seem to have had a similar structure. Incidentally, we will from now on call the Hsiung-nu "Huns" because Chinese sources begin to call them "Hu", a term which also had a more general meaning (all non-Chinese in the north and west of China) as well as a more special meaning (non-Chinese in Central Asia and India).
The Tibetans fell apart into two sub-groups, the Ch'iang and the Ti. Both names appeared repeatedly as political conceptions, but the Tibetans, like all other state-forming groups of peoples, sheltered in their realms countless alien elements. In the course of the third and second centuries B.C. the group of the Ti, mainly living in the territory of the present Szechwan, had mixed extensively with remains of the Yüeh-chih; the others, the Ch'iang, were northern Tibetans or so-called Tanguts; that is to say, they contained Turkish and Mongol elements. In A.D. 296 there began a great rising of the Ti, whose leader Ch'i Wan-nien took on the title emperor. The Ch'iang rose with them, but it was not until later, from 312, that they pursued an independent policy. The Ti State, however, though it had a second emperor, very soon lost importance, so that we shall be occupied solely with the Ch'iang.
As the tribal structure of Tibetan groups was always weak and as leadership developed among them only in times of war, their states always show a military rather than a tribal structure, and the continuation of these states depended strongly upon the personal qualities of their leaders. Incidentally, Tibetans fundamentally were sheep-breeders and not horse-breeders and, therefore, they always showed inclination to incorporate infantry into their armies. Thus, Tibetan states differed strongly from the aristocratically organized "Turkish" states as well as from the tribal, non-aristocratic "Mongol" states of that period.
The Hsien-pi, according to our present knowledge, were under "Mongol" leadership, i.e. we believe that the language of the leading group belonged to the family of Mongolian languages and that their culture belonged to the type described above as "Northern culture". They had, in addition, a strong admixture of Hunnic tribes. Throughout the period during which they played a part in history, they never succeeded in forming any great political unit, in strong contrast to the Huns, who excelled in state formation. The separate groups of the Hsien-pi pursued a policy of their own; very frequently Hsien-pi fought each other, and they never submitted to a common leadership. Thus their history is entirely that of small groups. As early as the Wei period there had been small-scale conflicts with the Hsien-pi tribes, and at times the tribes had some success. The campaigns of the Hsien-pi against North China now increased, and in the course of them the various tribes formed firmer groupings, among which the Mu-jung tribes played a leading part. In 281, the year after the demobilization law, this group marched south into China, and occupied the region round Peking. After fierce fighting, in which the Mu-jung section suffered heavy losses, a treaty was signed in 289, under which the Mu-jung tribe of the Hsien-pi recognized Chinese overlordship. The Mu-jung were driven to this step mainly because they had been continually attacked from southern Manchuria by another Hsien-pi tribe, the Yü-wen, the tribe most closely related to them. The Mu-jung made use of the period of their so-called subjection to organize their community in North China.
South of the Toba were the nineteen tribes of the Hsiung-nu or Huns, as we are now calling them. Their leader in A.D. 287, Liu Yüan, was one of the principal personages of this period. His name is purely Chinese, but he was descended from the Hun shan-yü, from the family and line of Mao Tun. His membership of that long-famous noble line and old ruling family of Huns gave him a prestige which he increased by his great organizing ability.
3 Struggles for the throne
We shall return to Liu Yüan later; we must now cast another glance at the official court of the Chin. In that court a family named Yang had become very powerful, a daughter of this family having become empress. When, however, the emperor died, the wife of the new emperor Hui Ti (290-306) secured the assassination of the old empress Yang and of her whole family. Thus began the rule at court of the Chia family. In 299 the Chia family got rid of the heir to the throne, to whom they objected, assassinating this prince and another one. This event became the signal for large-scale activity on the part of the princes, each of whom was supported by particular groups of families. The princes had not complied with the disarmament law of 280 and so had become militarily supreme. The generals newly appointed in the course of the imperial rearmament at once entered into alliance with the princes, and thus were quite unreliable as officers of the government. Both the generals and the princes entered into agreements with the frontier peoples to assure their aid in the struggle for power. The most popular of these auxiliaries were the Hsien-pi, who were fighting for one of the princes whose territory lay in the east. Since the Toba were the natural enemies of the Hsien-pi, who were continually contesting their hold on their territory, the Toba were always on the opposite side to that supported by the Hsien-pi, so that they now supported generals who were ostensibly loyal to the government. The Huns, too, negotiated with several generals and princes and received tempting offers. Above all, all the frontier peoples were now militarily well equipped, continually receiving new war material from the Chinese who from time to time were co-operating with them.
In A.D. 300 Prince Lun assassinated the empress Chia and removed her group. In 301 he made himself emperor, but in the same year he was killed by the prince of Ch'i. This prince was killed in 302 by the prince of Ch'ang-sha, who in turned was killed in 303 by the prince of Tung-hai. The prince of Ho-chien rose in 302 and was killed in 306; the prince of Ch'engtu rose in 303, conquered the capital in 305, and then, in 306, was himself removed. I mention all these names and dates only to show the disunion within the ruling groups.
4 Migration of Chinese