eme judicial authority for all criminal cases arising in Rome or
within a radius of one hundred miles of the city and also exercising
appellate jurisdiction in civil cases within the same limits, subject
however, to an appeal to the court of the princeps. For the rest of Italy,
the court of the praetorian prefect was now the highest tribunal in both
criminal and civil suits. By this time also the princeps had acquired
supreme appellate jurisdiction for the whole empire, a power which was
regularly exercised by the praetorian prefect acting in his place, In the
third century the Senate ceased to exercise any judicial authority
whatever.

As a result of the above processes the princeps became in the end the sole
source of legislative, administrative and judicial authority. The
republican magistrates had become practically municipal officers, and one
of them, the aedileship, disappeared in the third century. The complete
victory of the princeps over the Senate is marked by the exclusion of
senators from military commands under Gallienus, and their removal from
the provincial governorships in which they had continued to exercise civil
authority between the time of Aurelian and the accession of Diocletian.

*The friction between the Senate and the princeps.* It might be thought
that owing to the gradual admission to the Senate of the nominees of the
princeps that harmony would have been established between the two
administrative heads of the state. But although this new nobility was
thoroughly loyal to the principate, they proved just as tenacious of the
rights of the Senate as the descendants of the older nobility who
preserved the tradition of senatorial rule. Augustus and Tiberius
endeavored to govern in concord with the Senate by organizing an advisory
council appointed from the Senate, but their successors abandoned the
practice. The friction between the princeps and the Senate was due in part
to the realization that it was from the senatorial order that rivals might
arise and in part to the fact that those emperors who did not interpret
their position, as did Augustus, in the light of a magistracy responsible
to the Senate, were bound to regard the Senate's powers as restrictions
upon their own freedom of action, and as an unnecessary complication of
the administration. The chief services of the Senate were to provide a
head for the government when the principate was vacant, and to furnish the
only means for the expres