eror, appointed by him
and dismissed at his pleasure. At the basis of the administrative
organization lay the division of the empire into prefectures, dioceses and
provinces. By the close of the fourth century there were one hundred and
twenty provinces, grouped into fourteen dioceses, which made up the four
prefectures of Gaul, Italy, Illyricum and the Orient.(17) This division of
the empire into four prefectures was carried out under Constans and
Constantius. Until the death of Constantine I, the pretorian prefecture
had remained an office associated with the person of the emperor, and from
the time of Diocletian the number of praetorian prefects had corresponded
to the number of Augusti, each emperor appointing one for his own part of
the empire. This practice was followed by the sons of Constantine. But
after Constans had overthrown Constantine II he left the latter's
territory under the administration of a special prefect, thus establishing
the prefecture of Gaul. He afterwards appointed another prefect for
Illyricum, which was separated from the jurisdiction of the prefect of
Italy. When Constantius became sole emperor in 351, he retained the three
prefectures of Constans, and his own previous dominions constituted the
fourth, that of the Orient. In 379, Gratian, the emperor in the West,
transferred the Illyrian prefecture from his sphere to that of Theodosius,
his colleague in the East.

*The praetorian prefects and their subordinates.* Each province had a
civil governor, variously known as proconsul, consular, _corrector_ or
_praeses_, according to the relative importance of his governorship. The
provincial governors, with a few exceptions, were subject to the vicars,
who were in charge of the several dioceses, and who, in turn, were under
the administrative control of the four praetorian prefects, the heads of
the prefectures. The prefects and their subordinates were in charge of the
raising of taxes paid in kind and of the administration of justice for the
provincials. Italy was now divided into several provinces and Italian soil
was no longer exempt from taxation. With the exception of the population
of Rome, the inhabitants of Italy were upon the same footing as those of
the other provinces, with whom they shared the name of provincials.

*The central administrative bureaus.* The remaining branches of the civil
administration were directed by a group of ministers resident at the
court, with subordinates in t