. For in all these campaigns the
Turks had played an important part, and at the end they annexed further
territory in the north of Ch'i, so that their power extended far into
the east.

Meanwhile intrigue followed intrigue at the court of Chou; the mutual
assassinations within the ruling group were as incessant as in the last
years of the great Toba empire, until the real power passed from the
emperor and his Toba entourage to a Chinese family, the Yang. Yang
Chien's daughter was the wife of a Chou emperor; his son was married to
a girl of the Hun family Tu-ku; her sister was the wife of the father of
the Chou emperor. Amid this tangled relationship in the imperial house
it is not surprising that Yang Chien should attain great power. The
Tu-ku were a very old family of the Hun nobility; originally the name
belonged to the Hun house from which the _shan-yue_ had to be descended.
This family still observed the traditions of the Hun rulers, and
relationship with it was regarded as an honour even by the Chinese.
Through their centuries of association with aristocratically organized
foreign peoples, some of the notions of nobility had taken root among
the Chinese gentry; to be related with old ruling houses was a welcome
means of evidencing or securing a position of special distinction among
the gentry. Yang Chien gained useful prestige from his family
connections. After the leading Chinese cliques had regained predominance
in the Chou empire, much as had happened before in the Toba empire, Yang
Chien's position was strong enough to enable him to massacre the members
of the imperial family and then, in 581, to declare himself emperor.
Thus began the Sui dynasty, the first dynasty that was once more to rule
all China.

But what had happened to the Toba? With the ending of the Chou empire
they disappeared for all time, just as the Juan-juan had done a little
earlier. So far as the tribes did not entirely disintegrate, the people
of the tribes seem during the last years of Toba and Chou to have joined
Turkish and other tribes. In any case, nothing more is heard of them as
a people, and they themselves lived on under the name of the tribe that
led the new tribal league.

Most of the Toba nobility, on the other hand, became Chinese. This
process can be closely followed in the Chinese annals. The tribes that
had disintegrated in the time of the Toba empire broke up into families
of which some adopted the name of the tribe as th