e much less
affected by the corvee obligation than larger families with many sons.
It may be, therefore, that large families or at least sons of the sons
in large families moved away in order to escape these obligations. In
order to prevent irregularities, the T'ang renewed the old "_pao-chia_"
system, as a part of a general reform of the administration in 624. In
this system groups of five families were collectively responsible for
the payment of taxes, the corvee, for crimes committed by individuals
within one group, and for loans from state agencies. Such a system is
attested for pre-Christian times already; it was re-activated in the
eleventh century and again from time to time, down to the present.

Yet the system of land equalization soon broke down and was abolished
officially around A.D. 780. But the classification of citizens into
different classes, first legalized under the Toba, was retained and even
more refined.

As early as in the Han period there had been a dual administration--the
civil and, independent of it, the military administration. One and the
same area would belong to a particular administrative prefecture
(_chuen_) and at the same time to a particular military prefecture
(_chou_). This dual organization had persisted during the Toba period
and, at first, remained unchanged in the beginning of the T'ang.

The backbone of the military power in the seventh century was the
militia, some six hundred units of an average of a thousand men,
recruited from the general farming population for short-term service:
one month in five in the areas close to the capital. These men formed a
part of the emperor's guards and were under the command of members of
the Shensi gentry. This system which had its direct parallels in the Han
time and evolved out of a Toba system, broke down when short offensive
wars were no longer fought. Other imperial guards were staffed with
young sons of the gentry who were stationed in the most delicate parts
of the palaces. The emperor T'ai-tsung had his personal bodyguard, a
part of his own army of conquest, consisting of his former bondsmen
(_pu-ch'ue_). The ranks of the Army of conquest were later filled by
descendants of the original soldiers and by orphans.

In the provinces, the armies of the military prefectures gradually lost
their importance when wars became longer and militiamen proved
insufficient. Many of the soldiers here were convicts and exiles. It is
interesting to