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.

The small states in the west, in Kansu (the Later Liang and the Western,
Northern, and Southern Liang), were trading states: they lived on the
earnings of transit trade with Turkestan. The eastern states were
warrior states, in which an army commander ruled by means of an armed
group of non-Chinese and exploited an agricultural population. It is
only logical that such states should be short-lived, as in fact they all
were.

Sociologically regarded, during this period only the Southern and
Northern Liang were still tribal states. In addition to these came the
young Toba realm, which began in 385 but of which mention has not yet
been made. The basis of that state was the tribe, not the family or the
individual; after its political disintegration the separate tribes
remained in existence. The other states of the east, however, were
military states, made up of individuals with no tribal allegiance but
subject to a military commandant. But where there is no tribal
association, after the political downfall of a state founded by ethnical
groups, those groups sooner or later disappear as such. We see this in
the years immediately following Fu Chien's collapse: the Tibetan
ethnical group to which he himself belonged disappeared entirely from
the historical scene. The two Tibetan groups that outlasted him, also
forming military states and not tribal states, similarly came to an end
shortly afterwards for all time. The Hsien-pi groups in the various
fragments of the empire, with the exception of the petty states in
Kansu, also continued, only as tribal fragments led by a few old ruling
families. They, too, after brief and undistinguished military rule, came
to an end; they disappeared so completely that thereafter we no longer
find the term Hsien-pi in history. Not that they had been exterminated.
When the social structure and its corresponding economic form fall to
pieces, there remain only