d law. Higher than these were the service families
(_tsa-hu_), who were registered in their place of residence, but had to
perform certain services; here we find "tomb families" who cared for the
imperial tombs, "shepherd families", postal families, kiln families,
soothsayer families, medical families, and musician families. Each of
these categories of commoners had its own laws; each had to marry within
the category. No intermarriage or adoption was allowed. It is
interesting to observe that a similar fixation of the social status of
citizens occurred in the Roman Empire from _c_. A.D. 300 on.

Thus in the years between 440 and 490 there were great changes not only
in the economic but in the social sphere. The Toba declined in number
and influence. Many of them married into rich families of the Chinese
gentry and regarded themselves as no longer belonging to the Toba. In
the course of time the court was completely sinified.

The Chinese at the court now formed the leading element, and they tried
to persuade the emperor to claim dominion over all China, at least in
theory, by installing his capital in Loyang, the old centre of China.
This transfer had the advantage for them personally that the territories
in which their properties were situated were close to that capital, so
that the grain they produced found a ready market. And it was indeed no
longer possible to rule the great Toba empire, now covering the whole of
North China from North Shansi. The administrative staff was so great
that the transport system was no longer able to bring in sufficient
food. For the present capital did not lie on a navigable river, and all
the grain had to be carted, an expensive and unsafe mode of transport.
Ultimately, in 493-4, the Chinese gentry officials secured the transfer
of the capital to Loyang. In the years 490 to 499 the Toba emperor Wen
Ti (471-499) took further decisive steps required by the stage reached
in internal development. All aliens were prohibited from using their own
language in public life. Chinese became the official language. Chinese
clothing and customs also became general. The system of administration
which had largely followed a pattern developed by the Wei dynasty in the
early third century, was changed and took a form which became the model
for the T'ang dynasty in the seventh century. It is important to note
that in this period, for the first time, an office for religious affairs
was created which dealt m